Their real power , however , had been destroyed by the Persian invasion in 614 .
It was at this battle that some 12,000 Ghassanid Arabs defected to the Muslim side due to the Muslims offering to pay their arrears in wages .
Ghassanid Arabs ' real power , however , had been destroyed by the Persian invasion in 614 .
It was at this battle that some 12,000 Ghassanid Arabs defected to the Muslim side due to the Muslims offering to pay their arrears in wages .