Thurstan was a clerk under Kings William Rufus and Henry I. For a time he was Henry's almoner, responsible for distributing alms to the poor.* Henry selected Thurstan as the next Archbishop of York after the death of Thomas II of York. Thomas had refused to recognize Archbishop Anselm of Canterbury as his superior, and got his pallium from a papal legate and not bestowed on him by Canterbury. This was part of the Canterbury-York dispute.
In Thurstan's case, Anselm had been succeeded by Ralph d'Escures, who likewise would not support Thurstan's elevation to archbishop unless Thurstan professed obedience to Canterbury. This Thurstan would not do.
To be clear, he did not need to. Henry decided to quash the Canterbury-York controversy at the 1116 Council of Salisbury by ordering Thurstan to submit to d'Escures. Thurstan resigned the archbishopric instead of submitting. Meanwhile, however, Pope Paschal had sent him and the king letters that supported Thurstan against Canterbury. Thurstan's resignation was ignored. The next two popes repeated Paschal's orders, and in October 1119 Thurstan was in Reims being consecrated by Pope Calixtus II, even though Calixtus had earlier told King Henry that he would not consecrate Thurstan until the king gave his consent.
Henry was outraged, and vowed that Archbishop Thurstan would not set foot in England. Thurstan stayed on the continent with Calixtus. He also visited Henry's favorite sibling, his sister Adela of Normandy. Adela helped convince Henry to reconcile with Thurstan. Calixtus had also threatened interdict on England (no sacraments could be administered to the faithful) if Henry did not comply. When Adela retired from active life and entered the monastery of Marcigny at Easter 1120, Thurstan escorted her. A year later he ws recalled to England. (I can't help thinking Adela had a large hand in changing her brother's mind.)
One of Thurstan's more controversial moves was to make a bishop out of a man who was obscure of birth, boastful of his (fictitious) parentage, haughty and materialistic. Thurstan wanted to create more bishops to oversee more dioceses in northern England. One of these was Wimund, who was made Bishop of the Isles, including the Hebrides and the Isle of Mann. When Thurstan created a bishop for galloway, Wimund objected because he felt he had jurisdiction over Galloway. Wimund did more than object: he decided to compensate for the loss of revenue by losing Galloway that he became essentially a pirate, a story I told here.
Thurstan eventually resigned his position on 21 January 1140 in order to fulfill a lifelong goal of becoming a Cluniac monk at Pontefract. He died there on 6 February, after a two-week retirement.
Two years earlier, he had been essential in raising an army against the Scots. For the story of the Battle of the Standard, you'll have to come back tomorrow.
*The United Kingdom still has a Lord High Almoner.