Board Thread:Warhammer 40k General Discussion/@comment-69.143.134.163-20150419161351/@comment-8881468-20150520152043

sorry to blunder into your parade but the ultramarines absorbing another legions is fiction. there is actually only one soruce that states the possibility of that happening and even that is a rumor as mentioned by the people uttering that phrase while a ton of canon material disputes this with enough facts and arguments.

Also ciodexes state that empi found and met all primarchs and that all primarchs fought in the great crusade. the only primarchs who have little to no clue about the 2 lost ones are alpharius/omegon and corax, since they were found after the removal of the lost primarchs.