Magnate, from the Late Latin magnas, a great man, itself from Latin magnus 'great', designates a noble or other man in a high social position, by birth, wealth or other qualities. In reference to the Middle Ages, the term is often used to distinguish higher territorial landowners and warlords such as counts, earls, dukes, and territorial-princes from the baronage.
In England, the magnate class went through a change in the later Middle Ages. It had previously consisted of all tenants-in-chief of the crown, a group of more than a hundred families. The emergence of Parliament led to the establishment of a parliamentary peerage that received personal summons, rarely more than sixty families. A similar class in the Gaelic world were the Flatha. In the Middle Ages a bishop sometimes held territory as a magnate, collecting the revenue of the manors and the associated knights' fees.
In the Tudor period, after Henry VII defeated Richard III at Bosworth Field, Henry made a point of executing or neutralizing as many magnates as possible. Henry VII would make parliament attaint undesirable nobles and magnates, thereby stripping them of their wealth, protection from torture, and power. Henry VII also used the Court of the Star Chamber to have powerful nobles executed. Henry VIII continued this approach in his reign; he inherited a survivalistic mistrust of nobles from his father. Henry VIII ennobled very few men and the ones he did were all "new men": novi homines, greatly indebted to him and having very limited power.