A species of feudal tenure, which differed very slightly from a pure and perfect feud, being entirely of a military nature; and it was the first, most universal, and most honorable of the feudal tenures. To make a tenure by knight- service, a determinate quantity of land was necessary, which was called a “knight’s fee,” (feodum militare,) the measure of which was estimated at GS0 acres. Co. Litt. 09a; Brown.