This is a very touchy topic...
Allegro said:
Does this mean if those people in Bosnia had not converted to Islam centuries ago, today's B&H would comprise only Serbs and Croats, and the Bosniak identity would have never detached as something seperate?
Probably, regardless if the ethnicity existed before or not.
During the 19th century nationalism pretty much every catholic person was declared Croat and every orthodox christian a Serb regardless of geographical location or actual ancestry.
Which led to this magnificent ethnic distribution map;
-note, this is an old map...current ethnic distribution is a bit different because of, you know...war.
I suppose the same would happen to the "Bosniaks" if they had no third religion to separate them from the rest.
The main problem here lies with the fact that even though the name of Bosnians was present during the centuries before nationalism arose, there was no separate entity that could be called an ethnicity by today's modern view. The vast majority of medieval sources only mention Croats and Serbs in Bosnia and treat Bosnia solely as a geographical entity.
What makes things ever more confusing is the fact that a large percentage of modern muslim "Bosniaks" are not even descendants from Bosnians but rather muslim converts from Croatia, Slavonia, Dalmatia and Hungary(also Serbs) which were driven out and forced to migrate to Bosnia after those regions were retaken by the Habsburgs.
Take into account that pretty much every single muslim west of the river Vrbas is basically a Croat convert(Turkish Croatia);
http://en.wikipedia.org/wiki/Turkish_Croatia
along with the fact that the oldest known ethic group that were actually called "Bosniaks" are actually Croatian refugees that fled Bosnia and moved to Hungary/Austria during the Ottoman invasion;
http://en.wikipedia.org/wiki/Bosniaks_%28Croats_in_Hungary%29
...and you have an entire cluster bomb of confusion, ethnic tensions and...well...welcome to the Balkans