Wikipedia looks sound on clerical gaiters:
“Gaiters formed a part of the everyday clerical clothing of bishops and archdeacons of the Church of England until the middle part of the twentieth century. They were made of black cotton, wool, or silk, and buttoned up the sides, reaching to just below the knee where they would join with black breeches. Gaiters would be worn with a clerical apron, a type of short cassock reaching to just above the knee. The purpose of this vesture was originally practical, since archdeacons and bishops were presumed to be mobile, riding horses to various parts of a diocese or archdeaconry. In latter years, the clothing took on a more symbolic dimension.”
You can read all about bishops and gaiters, complete with pix of same (both bishops and gaiters) at this wonderful site here. There’s a bit about the association of bishops with windbaggery which gave rise to the expression “all gas and gaiters” here and a bit about the nickname of the sports team from Bishop’s University in Canada, “the Gaiters”, which comes from the legwear and not the reptile, here.
British Army gaiters replaced the puttees British and Commonwealth soldiers wore in the First World War, and which were, I believe, even more widely hated by the soldiers than gaiters …