The Lollards were the forerunners of the Baptists and there were some fragmentary congregations, although the movement for England as such was actually formed in Amsterdam in 1611, by John Smith; and then another Puritan, Thomas Helwys, risked coming to London in 1612 and he opened a Baptist church.
Whilst the movement agreed on rejecting infant Baptism, it disagreed on whether to be Arminian or Calvinist. The first founders had been Arminian, that salvation could be freely obtained from God's universal grace, but in 1633 there was a breakway of Calvinists who believed that salvation were predetermined by the all knowing God. The Arminians were called General Baptists and the Calvinists were called Particular Baptists.
The two wings could still agree on a Confession of Faith published by the Particular Baptists in 1644 where they ruled on baptism by immersion. Of course Baptist churches have always been independent and Bedfordshire and Hertfordshire churches, which came under the influence of John Bunyan, did not agree.
They grew during Cromwell's time but a period of strong oppression lasted from 1660 until 1689 after which there was growing toleration. Dissent grew but the Particular Baptists were more successful than the General Baptists. Some churches split along these lines. Baptists were inevitably divided at Salters Hall in 1719 when the General Baptists like the Presbyterians maintained confidence on the Bible alone (which allowed non-trinitarian liberalism to evolve) rather than adding creeds and other confessions of faith like the Congregationalists did.
Many General Baptists became Unitarian (giving the Unitarians added vigour and a broader social base) and in 1770 the General Baptist New Connection was formed as an effort to revive themselves whilst the Old Connection was disappearing into becoming enthusiastic Unitarians. Many Unitarian churches in Wales started out as Baptist. There were still some churches later which became Unitarian in outlook. This history of sliding into Unitarianism is one reason why Baptists to this day oppose Unitarianism and its involvement in Christian bodies. Yet Baptists, freely organised, had been openly divided in effect into liberal and orthodox, which forms a more hidden division through other mainstream churches today.
C. H. Spurgeon is probably the most famous Baptist, a preacher of many and differing sermons (three a week when in his longest ministry) for his returning audience. Born in 1834 of a Congregationalist family, he started his believing Christian identity (conversion) in a Primitive Methodist setting and then became a Baptist in 1850. So this was a pretty strong Calvinist and biblical preaching background, and he maintained this Particular Calvinism though a version that expanded the number God would save. He had what we call the gift of the gab in terms of holding an argument in a church setting. He preached at 22 years old and attracted people in so that the Metropolitan Tabernacle was built as a result in 1861 and he stayed there for the thirty one years he had left, including after he left the Baptist Union in 1877. His passionate and humorous preaching was about seeing above the real suffering of the present day and was delivered in plain language that ordinary people might understand as well as the great and the good, like Gladstone and Ruskin.
A much more liberal Baptist was John Clifford, born in 1836 in a working class family who also educated himself. He projected Christianity into the socio-political economy and ordinary world. He was happy with biblical criticism growing at the time, and thought there was no conflict between science and religion. He was happy to learn about God as people kept thinking and writing.
It took until 1891 for the General and Particular Baptists to be united in the Baptist Union of Great Britain and Ireland. Although the reputation of the Baptists is to be highly orthodox and strict, as a sort of Protestant version of Catholicism, and with much publicity given to American fundamentalist Baptists, there is still a General Baptist identity, and this is the liberal wing. I encountered quite a few of these people, and a tutor in favour of infant baptism, as well as the more doctrinal-biblical people, when at Luther King House, which used to be the Baptist College but became ecumenical. The other Baptist theological college is at Bristol.