Well, Oliver.. While I am not a musical historian by any means, I would say you were correct with the idea that bowed stringed instruments first appeared in the Orient.  Further east than Arabia, though.

Before the rebec, there was the Arabic rebab which was known in the 8th century.  But before that, there was the chuurqin in Mongolia that may date back to 600 AD or before.

The viol family of instruments though, isn't usually considered to have evolved until the 15th century.  I don't know how they figure such stuff.  But the rebec definitely looks like a "family member" of the violin/fiddle to me.  It was tuned and played similar enough.  The rebab and chuurqin and things like the morin huur and the erhu are maybe played differently enough to call a separate family of instruments, but the rebec?  Looks like an early fiddle/violin type instrument to me.

I was looking into the construction and history of some of the early bowed strings, particularly the rebec, since I've been toying with the idea of maybe making one or something like one.  They look like fun to play.  LOL