what did he start his career as?
A doctor of both civil and canon law.
William Greenfield
Greenfield next studied in Paris, where he became a doctor of both civil and canon law. 
what was the keldholme priory election dispute? The dispute occurred in Yorkshire, England. who was the dispute between? Archbishop of York and other nuns. and what was the dispute about? His candidate, Emma de Ebor', was  unacceptable by many nuns. who was the archbishop then? William Greenfield. when was he born? The date of his birth is now lost. where is he from? The eponymous Lincolnshire hamlet of Greenfield.
wiki:20666815
William Greenfield [SEP] Early life
Walter Giffard's brother was Godfrey Gifford, the Bishop of Worcester. Greenfield was the first of a number of Archbishops who ruled the northern English Archiepiscopal diocese as well as being significant statesmen during the fourteenth century. Before being made Archbishop he was variously: