Another force of them, supposedly fighting for Michael Doukas, invaded Greece before being driven out by Alexius I.  One of their leaders was ransomed by Danishmend Gazi after capturing and becoming the first king of Antioch during the first crusade.
A force of these people defeated Eustathios Palatinos under Drogo, while another was crushed by Ilghazi at the Field of Blood.  Another force of them, supposedly fighting for Michael Doukas, invaded Greece before being driven out by Alexius I.  One of their leaders was ransomed by Danishmend Gazi after capturing and becoming the first king of Antioch during the first crusade. His father conquered much of southern Italy, establishing a royal line in Sicily.  In addition to Bohemond and Robert Guiscard, their leaders include a man known as "the bastard" before his defeat of Harold Godwinson at Hastings.  For 10 points, name these people led by William the Conqueror.
A force of these people defeated Eustathios Palatinos under Drogo, while another was crushed by Ilghazi at the Field of Blood.  
Normans [accept Italian Normans or Italo-Normans before "bastard" is read]