Xavier fue capitan de los salamandras Salamandras.
A proud upholder of the Salamander's Promethean Cult, Xavier is said to have epitomised the Chapter's ideals more completely than any other Marine in their history. Dedicated to encouraging his fellows in feats of endurance and fortitude, it is said that when Xavier led them, the Salamanders never fell back before an enemy. As a sign of this dedication, he was entrusted with the keeping of "Vulkan's Sigil", a hammer-shaped relic believed to have been born by the Primarch Vulkan. He is also famed for having slain a particularly ancient and monstrous salamander with his bare hands.
Chaplain Xavier was killed leading an attack on a Dark Eldar raiding force on the planet Drykeena. Mortally wounded by blades several times over, Xavier refused to fall and fought on until all his foes were lying dead around him. Only then did he allow himself to sink to the ground, where his wounds finally overcame him. His body was laid to rest on Nocturne and his name is still spoken with reverence by the Salamanders.