Until the British ceded it to the French Mandate of Syria in 1923, according to the Sykes-Picot agreement of 1916. Syria "owned" the Golan for a total of 44 years, then lost it in a war of aggression on their part. With the wealth of archeological evidence of Jewish residency in the Golan, it's ridiculous to claim it's part of Syria. If anyone other than Israel deserves to own the Golan, it is the Druse, not Syria.
47 killed in clashes between ISIS, Syrian rebels near Turkey border, monitor says (Reuters)
from the article: Report: Syria willing to consider phased Golan pullout