Betrayal on Donatos
The Betrayal on Donatos began in M41, when the Word Bearers invaded the Imperium Industrial World Donatos. In response all five of the Knight Houses of Adrastapol, send their Knights to aid in Donatos' defense and are led to battle by High King Tolwyn Tan Draconis.
However, disaster struck during a battle with the Word Bearers, when the Adrastapolian Knight Houses Chimaeros and Wyvorn began attacking their fellow Knights, after their Thrones Mechanicum were tainted through Chaos witchery. In the bloody betrayal that followed, High King Tolwyn was killed and it fell to his son Danial Tan Draconis to rally the remnants of Houses Draconis, Pegasson and Minotos' forces. He then united his fellow Knights with the other scattered Imperial forces defending Donatos and launched a determined attack, that sought vengeance upon both the traitorous Houses and the Word Bearers.