Thomas Helwys, 1575 - 1616 was one of the joint founders of the Baptist denomination, along with John Smyth. Born to a wealthy family in Nottinghamshire, England, Helwys studied law in London and became a member of John Smyth’s Separatist church in Lincolnshire. Helwys and Smyth, with about 40 others, fled to Holland in the winter of 1606-07 to escape religious persecution and it was there that they founded the first Baptist church in 1609. As Smyth began to adopt Mennonite beliefs, Helwys championed Baptist beliefs by publishing the first Baptist confession of faith in 1611.

Helwys originated the distinctive Baptist belief in the separation of church and state and was the first to promote the idea of religious liberty and freedom of conscience for all, despite the danger of these views at the time. Helwys decided to return to England to face persecution for his faith. He founded the first English Baptist congregation in Spitalfields, London in 1612. He sent a copy of The Mistery of Iniquity, his appeal for universal religious freedom that was the first English document to state that religious liberty was a matter of personal conscience and a right for everyone that could not be overruled by any monarch or government, to King James 1. For this, he was imprisoned in Newgate prison. He died there in 1616.