Complex sentence: His "new institutions" altered the relations between the sovereign and the Hungarian lords: in the previous two centuries, a lord's position primarily depended on the income he received for his services to the monarch, hereafter their inheritable estates yielded sufficient revenues.
Split into simpler sentences: His "new institutions" altered the relations between the monarchs and the Hungarian lords. During the previous two centuries, a lord's status primarily depended on the income he received for his services to the monarch; after the introduction of the "new institutions", their inheritable estates yielded sufficient revenues.