Complex sentence: With the abandonment of farming, except on the immediate demesne, the need of the order for lay brothers disappeared; they probably died out altogether early in the fifteenth century, and there is no record of any at the dissolution.
Split into simpler sentences: With the abandonment of farming, except on the immediate demesne, the need of the order for lay brothers disappeared. They probably died out altogether early in the fifteenth century, and there is no record of any at the dissolution.