In the MIddle Ages, many clergy wore a vestment called an “amice” (Latin - “to cover”. An amice is a square piece of cloth that is placed like a woman’s scarf over the wearer’s head. The amice was worn over a black cassock but underneath other vestments, such as an alb. There are two small ribbons of cloth attached to two of the amice’s corners that are wrapped around the wearer’s chest and ultimately tied in front at the wearer’s waist. The wearer than dons an alb, and the top front of the amice is pushed backwards from around the wearer’s forehead to a position around the wearer’s neck to form a cowl-like collar over the alb. When the wearer leaves the sanctuary, the amice can be pulled back up over the head to serve as a head-covering in lieu of a birretta. The prayer that the clergy was instructed to speak while donning an amice was “place upon me, O Lord, the helmet of salvation, that I may overcome the assaults of the devil”.
~Dr. Gil Haas, St. Augustine of Canterbury Episcopal Church