Perfidian Gap

Overview
Perfidian Gap is a place where the Warp bleeds into reality. Because of this Chaos Daemons constantly attacks the inhabitants on the planets there.

Planets
There is a planet named Locrus there.

Military Conflicts
The Dark Angels attacked a army of Chaos Daemons on Locrus after the Daemons slaughtered a group of scientist on mission there.

Referances

 * 1) White Dwarf 341