Board Thread:Warhammer 40k General Discussion/@comment-5.65.81.205-20131020155613/@comment-108.20.1.54-20140514170052

Tzeentch stems from hope, ambition, and a longing for change. Slaanesh mostly from desire it does not necessarily need to be a degenerative excess as long as the means are pleasure, pain, and perfection. The Warhammer Fantasy page on Slaanesh if very good if you are interested.

As far as their births are concerned. The idea is like AWC 71 said but there is also some lore that they (the 4 bros) existed way before. One example. "The World Eaters were the very living expression of the Blood God's destructive power.......In this way, daemonkin might be part of the War-Given-Form, but the War-Given-Form was part of Umbragg and his XIIth Legion brethren's desire eternal to see the galaxy burn."-Rob Sanders, Legion of the Damned.

It seams to me that the 4 have been around since the beginning. And to say that Slaanesh was born in the 31st is sacrilegious to slaaneshi, see Daemon World by Ben Counter. It was probably him erupting into the status of a super power and not a minor god. There are about a thousand minor gods and not all daemons are affiliated to the 4. See Soulgrinder.