Lewis at Heidelberg, he had much friendly intercourse with the elector's brother, John Casimir, a bigoted Calvinist. His instructions ordered him to urge a reconciliation between the Lutherans and Calvinists of the Palatinate, and to demand certain sums of money which Queen Elizabeth had lent the late elector. In neither negotiation did he make much progress. He left Heidelberg while the Elector Lewis was still absent, and on Easter Monday he presented his credentials to the emperor at Prague. In defiance alike of his instructions and of diplomatic etiquette, he recommended the emperor, in an impassioned oration, to form a league of nations against the tyrannies of Spain and Rome—an appeal which the emperor naturally ignored. At Prague, Sidney paid a visit of condolence to the widow of the late Emperor Maximilian, and to his daughter, the widow of the French king, Charles IX; but he passed most of his time with Languet and his friends. On the return journey in April, Languet accompanied Sidney to Neustadt, where he met the Elector Lewis, and begged him to bring the strife between the Lutherans and Calvinists in his dominions to a close. He visited the Landgrave William of Hesse; but of all the princes and statesmen whom he interviewed, only John Casimir expressed approval of his project of a protestant league. At Cologne Languet left him, and, in conformity with new instructions and his own wishes, he turned aside from Antwerp to offer Queen Elizabeth's congratulations to William of Orange on the birth of a son. William received him with enthusiasm at Dordrecht, and invited him to stand godfather at the boy's baptism. Sidney left on William of Orange the best possible impression. The prince subsequently declared that her majesty had in Sidney one of the ripest and greatest counsellors of state that lived in Europe (Greville, p. 31). Very early in June Sidney arrived at the court at Greenwich, and on the 9th Walsingham wrote to Philip's father in Ireland: ‘There hath not been any gentleman, I am sure, these many years that hath gone through so honourable a charge with as great commendations as he.’
On 21 April 1577 Philip's sister Mary had married Henry Herbert, second earl of Pembroke [q. v.], and in July he hurried down to his sister's new home at Wilton to pay her the first of many visits there. But he soon returned to court in order to use his influence with the queen against those who were poisoning her mind as to his father's conduct of the Irish government. When the Earl of Ormonde, who had steadily resisted Sir Henry Sidney in Dublin, arrived on a visit to the queen, Philip was anxious to incite him to a personal encounter. In September he drew up an elaborate treatise, for the queen's perusal, in defence of his father's Irish policy (in Brit. Mus. Cotton MSS. Titus B. xii. ff. 557–9). It was divided into seven sections, of which the first three are missing, but enough survives to attest Philip's masterly grasp of the most difficult problem that confronted English statesmen. He proved his father's wisdom in levying taxation equally on the great Anglo-Irish nobles, the poorer settlers, and the native population, and attributed the frequency of disturbance to the unreasonable and arrogant pretensions of the nobility. For the moment the queen was pacified by his arguments, and Sir Henry enjoyed a few months' peace.
Philip's position at court was growing steadily in influence and dignity. In the summer of 1577 he entertained Philip du Plessis Mornay, an envoy from the French protestants, who brought an introduction to him from Languet. When in June 1578 Mornay and his wife paid a second visit to England, Philip stood godfather to an infant daughter who was born during the parents' visit. On new year's day 1578 he presented the queen not only with a cambric smock, the sleeves and collar wrought in black and edged with gold and silver lace, but also with a pair of ruffs laced with gold and silver, and set with spangles that weighed four ounces. The queen sent him in return gilt plate weighing twenty-two ounces. When the queen visited Leicester on the following May-day at Wanstead, Philip turned his literary gifts to account, and prepared a fantastic masque in her honour entitled ‘The Lady of May.’
Philip's wide intellectual interests led him at the same time to extend the circle of his friends beyond the limits of the court. ‘There was not,’ wrote Greville, ‘an approved painter, skilful engineer, excellent musician, or any other artificer of fame that made not himself known to him.’ But it was with men of letters that he found himself in fullest sympathy. When, in July 1578, representatives of Cambridge University waited on the queen, while she was staying at Audley End (near Saffron Walden), Gabriel Harvey [q. v.], who was a member of the deputation, met Sidney, who was in attendance on Elizabeth. That eccentric scholar at once fell under the sway of his fascination, and in his ‘Gratulationes Valdinenses’ which celebrated the royal visit he included an enthusiastic Latin eulogy of his new friend. It was doubtless Harvey who recommended
