Board Thread:Warhammer 40k General Discussion/@comment-24.254.200.119-20171110004941/@comment-8881468-20171110013204

if the emperor procreated throughout the milennia, those are not the emperor's children  but maybe some perpetuals (and that is very very very old fluff, talking ~early 90s), however, since emps has no idea when it comes to fatherhood, you can dismiss that notion outright.

the only sons of the emperor are the primarchs as far as 40k is concerned