The first reaction to Jameson's Raid by the London firm was an apparently bewildered letter to Phillips from Max Michaelis,dated 4 January 1896. The news had come like a thunderbolt, he said. "We can hardly see how such a mad proceeding as his could have ended otherwise than in defeat." They were in an awful state of suspense at the new premises at 120 Bishopsgate, [It had become necessary to hive off the Johannesburg side of the business. The new offices had the appropriate telegraphic address, "Glittered". The diamond dealing business stayed at Holborn Viaduct.] pestered by callers wanting to know what was really going on (not least by the hysterical Florrie Phillips, "hammering" on the door). Beit had cabled them on 30 December saying that Jameson had marched into the Transvaal and that every effort had been made to recall him. But apart from a Times report, mentioning a letter signed by Johannesburg residents appealing for help, that was all they knew. "We are not aware who the signatories of the letter are and we disapprove of the course taken, and further disavow any authority for anyone connected with our firm attaching his name to the document."

As they were soon to discover, Lionel Phillips had himself signed that notorious "women and children" epistle. And by the time Michaelis's letter had reached Johannesburg, Phillips was already locked up in Pretoria jail along with other leading members of the Reform Committee, including Percy FitzPatrick, who had previously burnt many incriminating papers. As has been remarked by an historian of the Corner House, it would thus seem, incredibly, that the firm's left hand did not know what the right was doing. Given the paucity of documents (many were deliberately destroyed), there will probably never be a satisfactory answer to this. Samuel Evans repeated that Julius Wernher was emphatically opposed to "methods of political force". Julius's admiration for Rhodes was more discriminating than Beit's, he said. "He [Julius] was not one who could blindly obey and follow...He hoped to break down the Boers' unreasonable attitude towards the Uitlanders by the more peaceful means of commerce and persuasion."

Whatever Jameson's motives were for launching himself into such an extraordinary reverse, the effects are still felt to this day. For the Boers' faith in British imperial honour and statesmanship had been destroyed, with an impact similar to the effect on the Indians in 1919 of the Arnritsar massacre. It has been said that Jameson rode because he felt he was fulfilling Rhodes's unspoken wish - a kind of parallel with the barons of Henry II. Maybe he had it in his head that both he and Rhodes were in some way invincible. Then again, he had been reading Macaulay's Essays, and some think he suddenly thought he was the incarnation of Clive. Or perhaps he was simply fed up with the shilly-shallying at Johannesburg, and thought he could push the Reformers and the rest of the citizens into action. This last was the more general view; at the Cape they called Johannesburg "Judasburg".

The plain fact was that he had not done his reconnaissance work and was not familiar enough with the lie of the land, and it had not entered his mind that at Christmas time Pretoria would be thronged with burghers up from the country.

Jameson had surrendered on the guarantee that his life and those of his surviving men would be spared. In spite of the clamour for his execution at Pretoria, he was handed over to the British government for punishment. But the fate of Phillips and the Reformers was more equivocal.

On 31 January Julius wrote about "these terrible times" to Georges Rouliot.

"Forgive and Forget" was hardly likely in Pretoria, but public opinion in Britain veered in favour of the rebels after the German Kaiser sent a telegram of congratulation to Kruger. There were indeed some virulent critics, chief among them being the Radical MP Henry Labouchere, owner of the newspaper Truth.

As for the wretched Florrie Phillips, she wrote an impassioned letter to The Times and never forgave Julius when he told her afterwards she should have held her tongue. Against her husband's wishes she sailed for South Africa.

Beit and Rhodes returned to London "to face the music". Beit looked ill but Rhodes seemed unperturbed. No doubt Julius was then enlightened to some extent. On 8 February he told Rouliot that Beit seemed better in health but "cannot stand mental strain'. The Johannesburg office was urging that Julius should come out, but he refused because of too much work and anxiety about Beit. As the trials in Pretoria dragged on, Julius heard from a youthful member of the Corner House, Raymond Schumacher, who had also been arrested but had had a prison sentence commuted, that whilst Phillips was "cheerful and sanguine", Friedie Eckstein was in a bad state of depression.

Eckstein did not throw in his hand immediately, but the threat remained. Then came the dreadful news that Phillips, Francis Rhodes, Hammond and Farrar had been sentenced to be hanged. Two days later the death sentence was commuted to fifteen years' imprisonment, and then later changed again to a fine of £25,000 each, with a signed undertaking that they would not again interfere in the affairs of the Transvaal Republic, which in effect meant banishment. FitzPatrick was sentenced to two years, imprisonment with a fine of £2,000. He was also released soon afterwards, having undertaken not to engage in politics for three years. Back in London, Jameson was fêted by his many admirers, especially female. He was tried and sentenced to fifteen months' imprisonment. After four months he was released because of illness.

Some of Phillips's letter-books had been seized by the Transvaal government and extracts published, which also reflected badly on the firm. Julius wrote in deep gloom about the future, after learning about Pretoria's "act of grace". "One sees no light anywhere and I am afraid the industry will go more and more to the dogs. We are anxious not to shut down but circumstances may force us and the precious metal market must remain where it is ... ...Of course the mines remain what they are but that is not sufficient for the investor and under present conditions we cannot see where a profit is to come from."

In a period when anti-Semitism was increasing across the Channel because of the Dreyfus case, the campaign against the Randlords began to take a more sinister turn, thanks in part to Labouchere's gibes at "Herr Beit" and the "Foreign Jew". A series of derisive articles appeared in Truth" 'Letters from Moses Moss of Johannesburg to Benjamin Boss, London". Johannesburg was now nicknamed "Jewhannesburg". Hilaire Belloc, at Oxford, wrote sarcastic poems about international financiers and the iniquities of imperialism, far removed in theme from the Empire heroics of novels by Rider Haggard and G. A. Henty.

Many of the new super-rich were building or buying houses in Park Lane or Piccadilly. Barney Barnato, at present renting Spencer House in St James's Place, was building a house in Park Lane. Siggy Netimann lived next to Lord Rothschild in Piccadilly. Alfred Beit's younger brother Otto, however, took over the Duke of Richmond's house in Belgrave Square. When Julius Wernher was asked whether he minded all the mud slung at Wernher, Beit, he made a sour little joke: "Why should I bear malice? They probably think I am only Beit's Christian name." Most people did assume that the Wernhers were Jewish.

In 1894 Beit had moved into the strange house built for him by Etistace Balfour at 26 Park Lane. It had two storeys and was described variously as an "enlarged bungalow" or "more like an encampment than a solid English house". The ground belonged to the Duke of Westminster, who had at first been uneasy about allowing an upstart from South Africa to build a house there. After hard bargaining, he had sent a last-minute message to Beit to the effect that he hoped he would spend at least £10,000 on his house. Beit's response was that he would be spending that amount on his stables alone.

Beit's special pride was his winter garden, a kind of conservatory, with a rock garden, ferns, palms, a tessellated pavement and an "electric fountain". The upper floor was almost an exact copy of his chambers in Ryder Street. During 1895 and 1896 Bode frequently stayed with him to advise on buying pictures, bronzes, and no doubt oriental carpets, on which he was also an expert.

Bode was tactfully to say that collecting was not Beit's "all engrossing passion", as had been in the case of Sir Richard Wallace and George Salting, the great benefactor of the Victoria and Albert Museum. Bode would therefore tip off Beit when exceptional bargains came on the market - and Beit was prepared to pay higher prices than Julius. No doubt there was many a quid pro quo after Julius made his donations to the Berlin museum, but it does seem that Julius was a more independent collector, and that Beit tended to get the cream of Bode's advice on pictures, some examples of his purchases being The Letter Writer by Vermeer (famously stolen from his nephew's house in Ireland in 1984) and six magnificent paintings on the theme of the Prodigal Son by Murillo.

The time has come to turn away from the dramas of South African politics, which were to continue for the rest of the decade and lead relentlessly to war, and to consider Julius as a connoisseur: a more peaceful but integral aspect of his life. A hundred years later the name Wernher was the more likely to be remembered in Britain for the extraordinarily diverse collection of masterpieces that he amassed in so short a time.

He had decided to find grander and more spacious premises to live in. Birdie's mother died on Boxing Day 1895, and this made it easier to think of moving eastwards from Bayswater to Mayfair. The opportunity came very soon with the death of Baron Maurice de Hirsch, financial adviser to the Prince of Wales and friend of Ernest Cassel, and who had made a fortune out of the Orient Express. Hirsch had lived in palatial style at Bath House, on the corner of Piccadilly and Bolton Street, facing Green Park and nearly opposite to where the Ritz Hotel now stands. The outside of Bath House was not particularly impressive, and looked rather like a fortress, with a high yellowish blank wall over Piccadilly.

But it had a big courtyard, many stables, an impressive staircase, and a large glass dome over the baltistraded central hall. Alexander Baring, first Lord Ashburton, had built it in 182 I, on the site of an older house belonging to the Earl of Bath, and the Emperor Alexander I of Russia had stayed there in 1814. Thomas Carlyle and his wife Jane had been friends of successive Lady Ashburtons in the 1850s and 60s, and had known the house well.

All details about the purchase of the leasehold of Bath House and its alterations were destroyed by bombs during the Second World War, as indeed was much of the business archives of the London end of Wernher, Beit. The house itself was pulled down in 1960, to make way for a building with an even less impressive façade. Photographs survive of the interior, showing some splendid French furniture, damask wall hangings, marble fireplaces and huge chandeliers. The plaster and woodwork were in the style of Louis XV, and it seems almost certain that these embellishments were executed for the Wernhers by Georges Hoentschel of Maison Leys, Paris.

Furniture and paintings had to be found for the house, and speedily. Again, apart from one notebook and a few scraps of paper, Julius's records have been mostly destroyed, though certain details about prices, dates and provenances have been gleaned through sales catalogues and research connected with exhibitions.

He had of course been buying more pictures since the acquisition of the Bermejo in 1890. A conventional though pleasant view of Eton College by Pyne was bought from Colnaghi for £250 in 1893, possibly as a present for Birdie on Harold's birth, since it hardly accords with Julius's later tastes. However, in 1895 he bought a major work, La Gamme d'Amour by Watteau, now in the National Gallery and the only example there of Watteau's work. This had been in the celebrated Mrs Lyne Stephens sale in Paris, and had been acquired from Agnew by Julius for £3,350. In the same year he bought another important picture from Agnew, Lady Caroline Price by Reynolds, costing £3,885. Over the next years he collected several other English portraits, including some Hoppners (in particular an attractive one of Henrietta Tracy as a child) from the Paris dealer Sedelmeyer, and a large easel portrait by the miniaturist Cosway.

Like other European nouveaux riches, Julius collected a number of eighteenth-century English family portraits. It was a time of agricultural depression and landowners were only too glad to sell their pictures to dealers for ready cash. Lords Carlisle, Brownlow and Ashburnharn were noted by Bode as among ready sellers, and some of their pictures were acquired for the museum in Berlin. Dutch interiors and genre pictures were also available and quickly snapped up as being easy to live with. Baron Ferdinand de Rothschild was already a leader in the market, but Americans such as Pierpont Morgan, Henry C. Frick and Isabella Gardner were not yet competitive. Thus, for those with the money, there were plenty of opportunities for building up an art collection of importance.

At least six other pictures were bought by Julius from Agnew, including in 1898 Titian's Giacomo Doria (£8,000) and Rest on the Flight into Egypt by Filippino Lippi (£3,300), and in 1901 a Virgin and Child between Two Saints by Francia (£1,700). From Colnaghi in 1899 he bought a small Rubens, Diana and her Hounds (£700), believed to have once belonged to Charles II of Spain.

Beit bought some thirty pictures from Agnew, including a Reynolds for £10,650, a figure that was evidently beyond Julius's limit. In the Agnew sales books one notes other purchases by people like Rodolphe Kann and Lionel Phillips. The Filippino Lippi had once belonged to Kann. Some stray jottings by Julius show that there were several good bargains, for instance, two church interiors by Pieter Neeffs, costing 52 and 18 guineas respectively in 1895, and three Guardi capriccios for £93, £170 and 220 guineas respectively.

Prices of course vary according to fashion or rarity, but they reflect a collector's character. A pound in the early 1890s would be the equivalent of about thirty pounds a hundred years later. It is a pity that we do not know how much Julius paid Sedelmeyer in 1900 for another exceptional work, Lady and Gentleman at a Harpsichord by Metsu, with wonderfully contrasting lights and shades. Originally belonging to the Hohenzollern family, it was bought by Sedelmeyer in Dresden for 42,000 Francs.

The highest known price paid by Julius for a picture was £8,000 for a full-length portrait by Reynolds of the Countess of Bellamont. Other important pictures included a Dutch interior by Pieter de Hooch, a Wouwermans, at least two van Ostades, a fifteenth-century Annunciation of the Venetian school, and a contemporary copy by Augustin Estève of Goya's portrait of the Duchess of Alba.

A feature of Julius's picture collection that differed from Beit's was a large proportion of paintings of the Virgin and Child, and it has been suggested that it was largely to please Birdie. These include one from the school of Botticelli and a little Hans Memling, bought in 1905 from a private source in Rome and in spite of some over-painting still a beautiful work.

The greatest acquisition of all was Christ Taking Leave of His Mother by Altdorfer, also now in the National Gallery. This was bought from Langton Davis in 1904 for an unknown price but certainly a great deal higher than the 23 guineas for which it had been sold at Christie's in 1884. Painted in about 1520, it is one of Altdorfer's most famous works, full of extraordinary pathos, unique because of Altdorfer's pioneer approach to landscape.

In spite of the Altdorfer and the Bermejo, the Watteau, the Metsu and the two Reynoldses, it is surprising that Julius with his huge and ever-increasing wealth did not attempt to collect yet more major masterpieces in paintings. It is perhaps unfair to compare his collection with that of Rodolphe Kann, the "premier amateur of France" as he was described in 1903. Kann possessed pictures by Bellini, Ghirlandaio, Bronzino, Tiepolo, Vermeer, Fragonard and Boucher, and no fewer than eleven Rembrandts, many of which through some clever manipulation by Duveen and Berenson found their way to Pierpont Morgan after his death. Jules Porgès also had a fine collection, chiefly of Dutch and eighteenth-century paintings, at his sumptuous mansion in Paris, 18 Avenue Montaigne.

The conclusion is that other aspects of Julius's collection engrossed him more, and indeed it is these that help to make it so individual. Like Beit, he had some remarkable bronzes, early majolica and Hispano-Moresque ceramics, but he also amassed Limoges enamels, Turkish ceramics, German stoneware and silver gilt, Palissy ware, clocks, tapestries and blue Sèvres. Among them were pieces of great importance. But one suspects that his ivories, mostly Byzantine, Carolingian and Romanesque, and his Renaissance jewellery were his chief passion.

It is easy to understand why Julius, who had dealt in diamonds nearly all his working life, should be fascinated by small, meticulously made works of art. His tenth-century ivory triptych of the Virgin and Child with angels and saints became famous among collectors. A relief of St Eustace, probably a book cover, may be even earlier in date. Julius collected around two hundred pieces of jewellery, including cameos, intaglios and finger rings, the majority being Spanish or German. The prize was a sixteenth century Spanish dragon with enamelled scales and set in emeralds. He also assembled a collection of German enamelled cap-badges and jewelled appliques or dress ornaments, dated around 1600.

His one surviving notebook was neatly kept, with details of prices and provenances between 1893 and 1897. Although objects were shown as having originated from Beresford-Hope, Baron Seillière, the Duc de Dino, Prince Soltikoff or Mrs Lyne Stephens, the notebook shows that Julius was in the habit of buying through the trade. Several items refer to the huge Friedrich Spitzer sale in 1893 in Paris where it was hailed as "la plus grande vente du siècle" and can still be identified at Luton Hoo. No pictures are listed in the notebook. The most expensive piece from the sale was a majolica plate dated 1525 by Giorgio Andredi of Gubbio at 25,050 Francs (£1,133.6s.). A Limoges plate signed by Pierre Raymond Cost 16,100 Francs and a sixteenth-century wax portrait 14,100 Francs. He also bought at the sale a fifteenth-century Book of Hours, a German sixteenth-century clock, a baroque enamelled pearl pendant, and a manuscript of Ovid's work ascribed to the "time of Botticelli" and originally part of Henry III's library.

Most important of all, there appear in the notebook "2 plates with the arms of Este Castel Durante XVI", apparently costing only £460. It would seem that these originated from the Gatterburg-Morosini sale at Venice in 1894. At any rate they must refer to two of the greatest treasures of the collection, part of the Este-Gonzaga set made for Isabella d'Este in about 1525 and now attributed to Niccolo da Urbino. Another plate from the service was bought at the Spitzer sale by Beit, for hanging on the wall at his house in Hamburg.

Altogether there are 230 items in the notebook from various sources, and they cost well over £60,000. So taking into account additional furnishings for Bath House, he would have spent at least £100,000 in those few years, not counting the Louis XV doorways and fireplaces which must have been imported from France. The other main dealers listed were Seligman, Bramer, C. Davis, Heckschner and Langton Davis. He bought furniture from Duveen and various bronzes from Bode, at remarkably reasonable prices. Some of the highest prices paid were for a pair of lapis and bronze eighteenth-century candelabra (£3,000) from Seligman and originally belonging to Prince Galitzine, and a fourteenth-century reliquary (£2,600) from Goldschmidt of Frankfurt. Three green Sèvres vases (£2,200) were bought from Sedelmeyer.

One of the most interesting pieces of Sèvres still in the collection, a vase, cost £257.55, and had been in the Lyne Stephens sale. A Régence bookcase from the same sale cost £616. The four Louis XV tapestries from Goldschmidt costing £2,000 must surely be the huge Beauvais tapestries, "Histoire du Roi de Chine", now hanging in the dining-room at Luton Hoo. A lovely emerald, ruby and diamond jewel of a falconer and two dogs, from the same source, cost £1,800. Other treasures that came through Goldschmidt were one of the "Emperor" tazzas in the collection, made in Augsburg in the sixteenth century for a Cardinal Aldobrandini, and a nautilus mounted in the seventeenth century at Ulm (£1,000). A Gobelin tapestry came from Seligman (£1,040). Bramer sold Julius a Limoges plate in grisaille by Pierre Raymond, depicting the Judgement of Paris, for £750 -a superb example- and a Castel Durante plate, c. 1525, of "Portia Bela", for a mere £70. From Beckschner he bought for only £200 a bronze copy of Michelangelo's Night in the Medici Chapel, and a twelfth-century casket from Cologne for £660.

Julius also had several dealings with Lord Carmichael, who was also a friend and for a while a Trustee of the National Gallery. Several years after Julius's death Carmichael wrote to Birdie comparing him to George Salting. He said that whilst it had been impossible for Julius to give as much time to his collections, he considered him more independent, "relying more on his own judgement and -I think, though this is to a great extent a matter of personal opinion- with better taste". He added that Julius was "far more modest than he need have been, or than most people are about their own skill in art matters".

A legend grew up that Julius was so busy that he could only see dealers over breakfast. A postscript to Carmichael's letter may explain how the story got about: "He used to chaff me because I thought he was the best judge of breakfast before looking at an object. He said it was because porridge always made one feel that it was well not to be over extravagant."

Carmichael also appended a long assessment of Julius as a collector: "Of the collectors of works of art whom I have known Julius Wernher was one of the most remarkable, not only because of what he did collect but because of what he did not collect." Julius, he said, often refused objects which he admired and which were offered at a reasonable price because he did not feel that they would raise the general level. He never bought things just because they were "pretty" - but when he did buy:

He commented on the originality of Julius's collection. At an exhibition he knew at once what would appeal to Julius.

On the score of originality of taste, and setting aside the English portraits and Pyne's Eton College, Julius's collection was essentially Continental. The German emphasis was not surprising, and maybe that included what he called the "splendidly ugly". He was not at all interested in, say, Chippendale furniture, or in nineteenth-century art. The French Impressionists probably horrified him. Photographs of his elaborately carved showcases at Bath House show how he loved juxtaposing different types of objects, instead of grouping them together as in a museum. "Every vitrine must be like a picture", he once said. He may indeed have bought certain things to please Birdie, but the impression is that the collection was very much his own, with some shrewd bargains, though in the first instance obviously influenced by Porgès and Rodolphe Kann.