Thomas Hoby was born at Leominster in Herefordshire in 1530. Though his parents were minor local gentry, a career in public life was made available to him through the considerable success which his much older half-brother, Philip, had achieved as a diplomat and courtier. Thomas studied at St John’s College, Cambridge, between 1545 and 1547, and then undertook a series of journeys to continental Europe, often in the company of Philip.

Thomas and Philip were both committed Protestants. This helped them to flourish under Edward VI, but caused them to lose favour under Mary I.