Like his namesake, the second Roger Williams named above, Sir Roger Williams was a member of the family of Penrhos , being the son of Thomas Williams and his wife, Eleanor , daughter of Sir William Vaughan . Anthony Wood says that he spent some time at Oxford — at Brasenose College . He became a soldier ; indeed, he was only 17 when he fought at S. Quentin . He spent almost the remainder of his life in Europe as a ‘ soldier of fortune ’; he was courageous and daring and became well-known as an expert in the art of military warfare . In April 1572 he was a member of a troop of 300 men who went to Flushing , under captain Thomas Morgan ( c. 1542 - 1595 , q.v.) , to assist the Dutch against the armies of Spain ; he fought also alongside of Sir Humphrey Gilbert and Sir Philip Sidney . From the Netherlands he went to Germany — for details refer to the D.N.B. He was knighted by the earl of Leicester — possibly in 1586 . His first publication was A Brief Discourse of War , 1590 ; this work being followed by Newes from Sir Roger Williams , 1591 . In 1618 there was published, posthumously, his Actions of the Low Countries ; of this there was a reprint in Somers 's Tracts , 1809 , a Dutch translation, Memorien van Roger Williams , appearing in 1864 . He d. at his home in London 12 Dec. 1595 , and was buried ( 23 Dec .) in S. Paul's Cathedral .