It has been stated that the feudal system was the most prominent institution of the Middle Ages. It was, however, absolutely incompatible with the spirit of modern times. The invention of gunpowder rendered the feudal army valueless; the increasing importance of commerce in time overthrew the feudal principles of land-ownership; while the modern theories of personal freedom and political equality were inconsistent with the feudal relations between lord and vassal. Feudalism in England received its death-blow in the War of the Roses during the fifteenth century; legally however, it only ceased to exist with the passage of the statute of 1660, upon the restoration of Charles II.