Here's an F u to the mando lovers:
Mandalore was falling. People had said it was impossible; that nothing could take it, not even the Empire itself.
They were wrong.
"So much for 'Unbeatable force' ", said a Catachan Guardsman, as he ripped a warrior's head from his struggling corpse. Resistance was, oddly enough, light. The enemy's troops were underequipped, poorly trained, and unbelievably incompetent. "How were these people feared?" thought a Kriegsman as his regiment advanced into the supposedly "impenetrable" city. They were held up for a moment as some engineers cleared up a barricade that the fleeing enemy had hastily erected. The Commissar in charge led the purge, as thousands of fleeing Mandalorians were gunned down by the pitiless las-fire of Emperor's Finest.
Up in orbit, the wrecked hulks of Mandalorian battle cruisers floated, scorched and pitted beyond recognition. Their ships had been woefully underprepared for an invasion fleet of this magnitude. It did not matter.
A few weeks later..
The ships orbiting Mandalore became aware of new arrivals in the system. They translated from the Warp, bearing the proud colors of the Ultramarines.
Primarch Roboute Guilliman of the Ultramarines Legion, along with the Hero of Graia, Captain Titus, had returned.
Shortly afterwards, Mandalore surrendered. With its fall, the way to Kamino lay open.