William Aylesbury (1615 – 24 August 1656), was an English translator from the Italian.
Aylesbury, although a supporter of Charles I, obtained an office under the Commonwealth, was the son of Sir Thomas Aylesbury; in 1628 he became a gentleman commoner at Christ Church, Oxford, and took his bachelor's degree in 1631, at the early age of sixteen (Wood, Fasti Oxon. i. 460). His sister Frances married Sir Edward Hyde, afterwards Lord Clarendon. Although possessing a large fortune, Aylesbury soon afterwards became, at the invitation of Charles I, governor to the young Duke of Buckingham and his brother, Lord Francis Villiers, and travelled with them through France and Italy. In 1640 Aylesbury was residing at Paris, and in his correspondence with his brother-in-law, Sir Edward Hyde, which is preserved in the Bodleian Library among the 'Clarendon Papers,' bitterly lamented the course of English politics under the Long Parliament. In the middle of May 1641 he returned from Paris to London with the Earl of Leicester, the English ambassador at the French court, with whom he had been apparently living in an official capacity for some months (Cal. State Papers, 1640-1, pp. 558, 561, 562). Shortly afterwards he presented his former pupils to the king at Oxford, who promised him the next vacancy among the grooms of the chambers, but the promise was never fulfilled, and Aylesbury continued in the service of the Duke of Buckingham, as his agent, until the final defeat of the royalists.
During his interview with Charles I, the king urged Aylesbury, who was well acquainted with Italian, to continue a translation of Enrico Caterino Davila's 'History of the French Civil Wars,' which he had just begun, and during the following years he was mainly engaged in the work; but he was only in England at intervals, and witnessed his royal patron's disasters from the safe distance of Paris or Rome. He and his friend, Sir Charles Cotterel, who materially aided him, received, however, frequent encouragement from the king. In spite of his political troubles, Charles, in fact, read through the whole of the manuscript before the book was printed. The translation was published with a dedication to the king in 1647, and bore the title, The Historic of the Civil Warres of France, written in Italian by H. C. Davila. Translated out of the originall. London, 1647, fol. On the fall of Charles I, Aylesbury sought refuge with his father, first at Amsterdam, and afterwards at Antwerp; and he took under his protection his sister, Lady Hyde. But his poverty, caused by the confiscation of the property of his family, forced him in 1650 to return to England, and retiring to the neighbourhood of Oxford, he lived on the charity of his more fortunate friends. Early in 1656, however, he obtained the office of secretary to Major-General Robert Sedgwick, who had just been appointed Governor of Jamaica, and finally left England. For a few months he took an active part in the government of the island, but he died on 24 August 1656. A letter conveying the news of his death to Secretary John Thurloe describes him as 'a man well versed in the weighty affairs of state, who in his counsels and advice, both to army and fleet, was very useful, for the want of which we shall have more and more to grieve.' Aylesbury's translation of Davila was republished in 1678 with a preface by Sir Charles Cotterel, who there claimed for himself the execution of the greater part of the original version.