Basically, the title says it all.

After reading Vivec's sermons I got an impression that in the beginning of his career Nerevar was just a mercenary captain and didn't belong to House Indoril.
Then some time ago I saw a post here in which it was told that Nerevar was born into a minor House (now extinct, like House Sotha) before he was accepted to Indoril. The name of this House was also mentioned. Unfortunately, now I can't find this post.

So, was Nerevar born into House Indoril or became Indoril through marriage with Almalexia? And is there a definitive answer to this question or speculations are possible?

Now that is an interesting though. We all, biased by society - naturally assumed that a wife takes her husband's name, but fantasy cultures don't have to work that way (still, most do, because gender topics are somehow taboos).

Once Nerevar had becoem great, House Indoril would, naturally, have claimed he was one of them, maybe even faked documents, just to be sure.

I dont know for sure, but his full name is Serjo Indoril Nerevar Mora. So unless he was of two houses, its actually likely that Ayem was in fact of Indoril and house Mora was absorbed.

I thought Nerevar FOUNDED house Indoril.

Yeah that was my assumption.. haha.

Actually, Nerevar was indeed just a mercenary captain, who later became Hortator and then founded House Indoril.

You'll want to look it up in Vivec's sermons, http://uesp.net/wiki/Lore:36_Lessons_of_Vivec,_Sermon_5, for example.

Thats a feasible possibility, but then why Indoril of all things? I wonder what it means, we know what Mora means.