There is not much web info on Keach, but one great introduction is Haykin's little book entitled, "Kiffin, Knollys and Keach: Rediscovering our Enlglish Baptist Heritage" by Carey Publications (1996).
This article is taken from fontes, the web site of many of Dr. Haykin's writings.
Benjamin Keach (1640-1704)
Benjamin Keach found himself in trouble with the state on more than one occasion. For instance, in 1664 Keach was arrested on a charge of being “a seditious, heretical and schismatical person, evilly and maliciously disposed and disaffected to his Majesty’s government and the government of the Church of England.” It appears that a children’s primer which Keach had written containing reading lessons, simple instruction in punctuation and arithmetic, and lists of words of one, two, or three syllables had been read by the Anglican Rector of Stoke Hammond, Thomas Disney, and reported to the government authorities as not only unfit for children, but positively seditious. No copies of this primer exist today. At the time of his trial all copies of it were destroyed; though we are told Keach rewrote it later from memory and published it as The Child’s Delight: or Instructions for Children and Youth. The original primer was deemed heretical especially because of references to believer’s baptism and Keach’s interpretation of the Book of Revelation. Put on trial on October 8, 1664, Keach was found guilty, imprisoned for two weeks and fined £20, a considerable amount in those days for a poor Baptist preacher.
In addition to these punishments, Keach had to stand for two periods of two hours each in the pillory, a wooden framework that had holes for the head and hands of the person being punished. Generally the pillory would be placed in the town or village square where the offender could also be subjected to various forms of public ridicule. On this occasion, however, Keach took the opportunity to preach to the crowd that gathered around. “Good people, “ he began during his first time in the pillory, “I am not ashamed to stand here this day, … my Lord Jesus was not ashamed to suffer on the cross for me; and it is for his cause that I am made a gazing-stock. Take notice, it is not for any wickedness that I stand here; but for writing and publishing his truths, which the Holy Spirit hath revealed in the Holy Scriptures.” At this point a Church of England clergyman, possibly the local minister, sought to silence Keach by telling him that he was in the pillory for “writing and publishing errors.” Keach, recognizing a golden opportunity for public debate and witness, quickly replied, “Sir, can you prove them errors?” But before the clergyman could respond, he was rounded on by others in the crowd, who knew him to be a drunk. Keach proceeded to speak in defence of his convictions despite a couple of further attempts by the authorities to silence him. Eventually he was told that if he would not be silent, he would have to be gagged. After this he was silent except for his quoting of Matthew 5:10: “Blessed are they which are persecuted for righteousness’s sake: for theirs is the kingdom of heaven.”
On another occasion, when Keach was apprehended in the act of preaching by a troop of cavalrymen, four of them were so enraged with him that they swore that they would trample him to death with their horses. He was accordingly bound and forced to lie on the ground. But just as they were about to spur their horses down upon their victim, their commanding officer arrived and prevented them from harming Keach, who almost certainly would have been killed
If anyone knows of some excellent on-line bigraphy of Keach I would be most interested in linking to it!
You can also purchase this book on Keach from Joshua Press.