Sorry to be THAT GUY but...
781.M31 = Abaddon's 1st Black Crusade. On Uralan, the Despoiler secures the daemon weapon Drach'nyen. The First Battle of Cadia.
544.M32 = An Ork Warboss known only as the Beast forms an enormous army of Orks that rampages across the Imperium. He is eventually stopped at great cost to the Adeptus Astartes.
546.M32 = The Beheading: Grand Master of the Officio Assassinorum Drakan Vangorich has the High Lords of Terra murdered. The rogue Master of Assassins is tracked down and slain by a Space Marine strikeforce drawn from the Imperial Fists, Halo Brethren and Sable Swords. Only a single Space Marine survives the campaign.
552.M32 = The space hulk Da Iron Worm carries marauding orks across the Uhulis Sector. They destroy Battlegroup Azezel, the Fortress Worlds Armstrong and Velgagrad, and the Forge World Temaxia, leaving the Ul-Seraph Cluster defenceless. A warp storm blasts Da Iron Worm off course and into the Empyrean. Scout vessels determine that its course took it into the Dark Marches and is never heard from again.
597.M32 = 2nd Black Crusade, a failed attack on the defences of Cadia.
So there is 763 years between the 1st Black Crusade and The Beast. But lots of interesting stuff going on around the same time as The Beast!