In 1534, Henry VIII formed the Church of England when Pope Clement VII refused to give the king what Henry wanted: a divorce from his first wife (Catherine of Aragon) so he could marry his second (Anne Boleyn). Breaking with the Catholic Church, the king closed monasteries in England, allowed the clergy to marry, and declared himself head of the church. Soon all English citizens were required to be members of the Anglican Church.
Although Henry's actions were drastic, not everyone agreed his reforms were sufficiently radical. People who embraced the theological teachings of Martin Luther and John Calvin (who stated, among other things, that people could have a personal covenant with God) wanted to "purify" the Church of England by simplifying and reorganizing it. Most of those "Puritans" (some of whom later came to America) thought the Anglican Church could be restored from within.
Other English citizens, believing the existing church was beyond repair, wanted to separate from it altogether. One group of those "Separatists," in 1607, formed a new church - an illegal action under English law - in Scrooby, a small Nottinghamshire village. William Bradford (a 12-year-old orphan when he'd first met leaders of the breakaway congregation) became a member of that separatist group.
Because they were breaking the law, by forming their own church, members of the Scrooby congregation were fined and/or imprisoned. Understanding that Holland, by 1607, enforced religious toleration, the group decide to move to that country (also called The Netherlands or the Low Countries). There was a problem, however. Moving, for them, was illegal:
For in 1607 we read, this "groupe of earnest professors of religion and bold assertors of the principle of freedom and personal conviction in respect to the Christian faith and practice" had formed the resolution to seek in another country the liberty they found not at home. But it was as unlawful to flee from their native land as to remain in it without conforming, for the statute of 13 Richard II, still in force, made emigrating without authority a penal crime. (Addison, A.C. The Romantic Story of the Mayflower Pilgrims. Boston: L.C. Page & Co., 1911. 16-19)
If it was a crime to leave, and a crime to freely worship if they stayed, what choices did they have? Whatever their decision, they would have to defy the law.
They chose to leave. But defying the law, if one is caught, has consequences. Sometimes those consequences produce time behind bars - or in dungeons.