Anselm
"Anselm held the position of archbishop of Canterbury from 1093 to 1109. A Benedictine monk, philosopher, and theologian, he stands as one of the most significant thinkers in the history of the Western church." While Anselm's name is widely known, his impact is not. In his article in the current edition of Tabletalk magazine, R.C. Sproul looks at this man's life and influence.
"His influence is not due to the sheer volume of his writings but to his ability to expound profound subjects biblically and thoughtfully in just a few words. In general, the assumption exists that to make a significant contribution to the body of literature that shapes scholarly thought requires the production of massive tomes. Anselm’s impact completely overthrows this notion."
You would do yourself a favor to read this article titled simply "Anselm."