Principate
The Syrian army accounted for three legions of the Roman army, defending the Parthian border. In the 1st century, it was the Syrian army that enabled Vespasian's coup.
Syrian province forces were directly engaged in the Great Jewish Revolt of 66-70 CE. In 66 CE, Cestius Gallus, the legate of Syria, brought the Syrian army, based on XII Fulminata, reinforced by auxiliary troops, to restore order in Judaea and quell the revolt. The legion, however, was ambushed and defeated by Jewish rebels at the Battle of Beth Horon, a result that shocked the Roman leadership.
The Syrian legion later took part also in the crackdown upon Judaea during the Bar-Kokhba War of 132-136.
Read more about this topic: Syria (Roman Province)