As late as the Horus Heresy, the Yndonesic Bloc, though an integral part of the Imperium of Man, retained a distinct regional identity. For example the contacts within the Fartraders' Guild of this bloc helped the Cult of the Hedonic Lord to rise to power somewhere between M33 and M39 leading to mass rebellion that was ended only during the Siege of the Eternity Gate.
- 1: Mechanicum (Novel) by Graham McNeill, Chapter 2.05
- 2: Codex: Adeptus Custodes (8th Edition), pgs. 30-31 - The Tale of the Ten Thousand: Siege of the Eternity Gate
- 2: Horus Rising (Novel), Part One, Chapter Seven