William Brewster was born around 1566. He was an Elder and teacher of the church in Leiden, and he continued his leadership in Plymouth. William was involved with printing religious materials in Leiden, which forced him to go into hiding from English authorities before the departure of Mayflower. He was the highest ranking Separatist church official to voyage on Mayflower.

William married a woman named Mary around 1592, with whom he had 5 surviving children. Two of their children were Mayflower passengers, while the elder three joined the family in America later. He died in Duxbury in 1644.