I figure the name was far more widespread then what I could find in my limited segments. Searched a few baby name websites and they didn't even give me a variation, you seemed to of found what I was looking for. names often change with language in translation, or with the development of a language over time. I.E. France lost the R in it's alphabet once, but regained it some years later, this caused a calamity of spelling types in various dialects and entirely new names. It wasn't until the French Revolution that French became the National language, widespread and formatted in regulated spelling system.
Or take my second surname for example. It's "Resende", it's not only a territory, but it's a Visigoth name which became common in Portugal. The name means "Son of Resendo" so the original meaning, but the meaning of Resendo is "Path of Advice" Then there are a dozen variation of the former and the latter in both spelling and pronunciation.
Sorry off track, but you get the idea why I was trying to figure out the name? I was hoping to find out the following.
1.Origin of why the name was chosen.
2.Meaning of the name
3.Evolution of the name.
4.Original meaning of the name
5.and finally, if there is a Romanian variation of the name.
I was hoping that we could not only have a little fun digging into this mystery, but also, add some degree of realism to the Clan's origins and possibly find some sort of correlation to the Dracula novels or games.
It would help if we had a few details from the game explained, to help narrow this down immensely. The obvious first one is of course why the name was chosen. BUT the second most important that could easily help us narrow a search would be Leon Belmont's nationality. That alone would narrow everything down since plot wise it seems that the Clan didn't originate in Romania (though originally it did with Sonia's plot before she was ret-conned out.) We could also research Mathias, but that is equally daunting since his name is possibly Swedish and or simply derived from around the Baltic Seas.
I have a strong suspicion that Leon is actually Germanic himself because of not only the German variance of the name, but since the plot seems to coincide with the Holy Roman Empire (A mostly Germanic Empire), a time when the Church was reaching the height of it's power, kings were weakened, and before the major splintering of kingdoms. The fact his lords and the church wouldn't let him sortie seems to imply this. This map 2 years after the game seems to support this theory.
http://www.euratlas.net/history/europe/1100/1100.jpg