Which War is Which?

There were three Wars for Armageddon:

The First War, fought between the invading World Eaters and allies under Primarch Angron, and the defending Armageddon Imperial Guard and Defence Forces, supported by the Space Wolves and Grey Knights.

The Second War, fought between the invading Waa-Ghazghkull and the defending Armageddon Imperial Guard and Defence Forces, supported by the Blood Angels, Ultramarines and Salamanders.

The Third War, fought between the returning Waa-Ghazghkull and the defending Armageddon Imperial Guard and Defence Forces, supported by dozens of Space Marine Chapters.

Image from the Second War for Armageddon, depicting Blood Angels fighting Orks.