Robert de Montgomerie held Petworth till 1102, when he defied the king and lost it.

Adeliza, widow of Henry I., having a brother Josceline de Louvaine whom she wished to benefit, Petworth was given to him.

Josceline married Agnes, daughter of William de Percy, the descendant of one of the Conqueror's chief friends, and, doing so, took his name.

In course of time came Harry Hotspur, whose sword, which he swung at the Battle of Shrewsbury, is kept at Petworth House.

The second Earl was his son, also Henry, who fought at Chevy Chase; he was not, however, slain there, as the balladmonger says, but at St.Albans.
Henry, the third Earl, fell at Towton; Henry, the fourth Earl, was assassinated at Cock Lodge, Thirsk; Henry, the fifth Earl, led a regiment at the Battle of the Spurs; Henry, the sixth Earl, fell in love with Anne Boleyn, but had the good sense not to let Henry the Eighth see it.