For the first two years of the reign of William II, he retained his father's chief advisor, Lanfranc, the Archbishop of Canterbury. After Lanfranc's death in 1089, however, William appointed Anselm as Archbishop. Anselm had been born in Aosta, now in north-western Italy, but migrated northwards partly in emulation of the eminent Lanfranc. His appointment as archbichop led to protracted conflict with the king. As a condition of accepting the position, Anselm insisted that William accept Urban II as Pope, rather than the "Antipope" Clement III. In addition, disagreements developed since Anselm advocated Gregorian reforms that William was not prepared to implement.
Editors. "Anselm becomes Archbishop of Canterbury". The Literary Encyclopedia. First published 31 July 2012
[http://www.litencyc.com/php/stopics.php?rec=true&UID=1950, accessed 23 March 2017.]