Board Thread:Warhammer 40k General Discussion/@comment-173.238.152.115-20140122073927/@comment-6078851-20150409153249

whatever happened to the 2 lost primarchs occured before the heresy, unquestionably, but that doesn't mean their records were expunged at the same time. their records could have existed for a long time before someone in high-government thought that maybe such records shouldn't be known about.

but what people really question is what the hell could they have done that required their records be deleted? the heresy is largely unknown of by the populous of the imperium as the government don't like folks to know that the imperium was nearly destroyed by its own supersoldiers, however... horus, the favourite son of emps and warmaster who became the prime agent of chaos and was so responsible for the civil war that they named it after him, hasn't been expunged from records! so if he could almost destroy the imperium by becoming the pre-eminent champion of chaos and caused an unprecedented civil war but his records still exist... well, i can't think what the 2 primarchs could possibly have done that would be deemed so much worse that no trace of their records exist :)