In 1072, a church council was held at Windsor to resolve the dispute over primacy between the archbishops of Canterbury and York in the reorganised English Church following the Norman Conquest of 1066.

The conflict had arisen between Lanfranc ⓘ, Archbishop of Canterbury, and Thomas ⓘ, the newly appointed Archbishop of York. Lanfranc maintained that Canterbury held primacy over the entire English church, while Thomas argued that York was an independent metropolitan see.

The council, held in the presence of William ⓘ, ruled in favour of Canterbury. York was required to acknowledge Canterbury’s primacy, and Thomas made a formal profession of obedience to Lanfranc.

Although the decision strengthened Canterbury’s authority, the question of primacy between the two archbishoprics remained a recurring issue in English ecclesiastical politics for centuries.