He accompanied Sir Thomas Hoby on an embassy to France in 1566, and resigned his Magdalen fellowship in 1569.
[1] Between 1575 and 1587 Tomson represented Weymouth and Melcombe Regis in the House of Commons, and he was member for Downton in 1588–9.
According to his epitaph he travelled in Sweden, Russia, Denmark, Germany, Italy, and France; was conversant with twelve languages; and at one period gave public lectures on the Hebrew language at Geneva.
He was employed in political affairs by Sir Francis Walsingham, after whose death he retired into private life.
[1] Tomson died on 29 March 1608, and was buried in the chancel of the church at Chertsey, Surrey, where a black marble was erected to his memory with a curious Latin inscription.