[3] Early in 1549 he was sent to the king of France, and in October 1550 Sir John Mason suggested his despatch as special commissioner to the same monarch, "being fully qualified by his knowledge of the language and previous experience".
On the re-establishment of the order in April 1557 Shelley was made turcopolier, an office second in dignity to that of grand prior, which was conferred on Thomas Tresham I (died 1559).
The efforts made by the English ambassador at Madrid to induce him to return to England were in vain, but Shelley protested his complete loyalty to the queen.
As the relations between England and Spain grew strained, Shelley left for Malta, but at Genoa was recalled by Philip to go as his ambassador to Persia.
He established himself at Venice on the invitation of the seignory, and there sought to ingratiate himself with the English government by sending secret intelligence of jesuit and other intrigues against Elizabeth I of England.
He also made himself useful by looking after English commercial interests, and in 1583, in answer to his repeated requests, he was granted leave to return to England with liberty to practise his religion.
[6] But he was still under suspicion; he had held communications with William Parry (died 1585) at Venice; most of his relatives in England were recusants, and his nephew Richard Shelley was implicated in treasonable proceedings, for which he was examined by the council.
To illustrate these, two of Shelley's medals preserved in the king's collection (now in the British Museum) were engraved by James Basire, and published as a frontispiece to the volume.