Ulzar Sadosh’s Reviews > The Horus Heresy Vol. IV: Visions of Death: Iconic images of the Imperium, betrayal and war > Status Update

So, yeah, my journey through Visions of Heresy is slowly nearing the end. It seems that's where the whole War in the Webway thing was introduced.
Also, it seems it has Siege of Terra starting just after the end of Istvaan V.