Although possessing a large fortune, Aylesbury 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 in 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.
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 with in this work.
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 Cotterell, who there claimed for himself the execution of the greater part of the original version.