Adeliza of Aquitaine (1103-1151) was the wife of Henry I of England and sister of Jocelin I of Louvain. Another bearer was Adelaide of England (c. 1055-?), daughter of William the Conqueror, who is sometimes referred to as Adeliza for some reason.
Now, I'm theorising that Adeliza is a contracted, altered form of Adalheidis (see Adelaide). I'm thinking it could've evolved like this: Adalheidis → Adalis → Adaliz → Adaliza → Adeliza. Or maybe some sort of similar path?
Does this look like sound theory to you guys? Or could it be that Adeliza arose from a different source?
Miranda "...his fingers trailing over your belly, your thighs quacking..." — From a The Lord of the Rings crapfic