The Witch-finder General of Essex, from 1644 to 1647. He was probably born in Little Wenham in the 1620s, his father a parson. He went on to practice law in Ipswich, and then moved to Manningtree and Mistley, where he "examined" his first witches at the Thorn Inn.
Believing that witches fed familiars with their blood, one of Hopkins' methods of interrogation was to keep the "witch" awake and on surveillance, even for days on end, so that the familiar couldn't sneak in and feed. The result was sleep deprivation, wherein the suspect could be coaxed into confessing to almost anything, including Satanic pacts.* Another method he would use was a retractable blade--it was believed that witches could be stabbed and not have a mark on them, and this was his way of "prooving" that. Suspects were strip-searched for familar marks (often a third nipple). Finally, one of Hopkins' favorite methods was the infamous swimming test--if she floats then she is a witch; if she drownds, she was innocent, and now in heaven with God.**
Hopkins himself never touched the victims--he would recruit local people or his associates to do the dirty work while he questioned them. This kept him clear of any possible charges stemming from his work; charges were never filed anyway, though.
Hopkins was paid rather well for his work; he convicted at least 209 individuals--men, women, and children. Most were hanged, while the fate of many others are unknown.
Matthew Hopkins died in August of 1647, but the witchhunts were far from over. There are two accounts of his death--either from tuberculosis, or hanging after being accused of witchcraft.
* A tactic still used in most countries, including the United States
and United Kingdom
** A not-too-dissimilar argument for the death penalty was given by President George W. Bush while govenor of Texas, who said that if an innocent or reformed person--in this case I believe it was Carla Faye Tucker, who repented of her brutal murders, became a born-again Christian, and had many people pleading for clemency and a life sentence--has been put to death, then at least that person is now with God in heaven.