With the Byzantine army routed, the Muslims quickly recaptured the territory they had conquered prior to Yarmouk. Abu Ubaida held a meeting with his high commanders, including Khalid, and decided to conquer Jerusalem. The Siege of Jerusalem lasted four-six months, after which the city agreed to surrender, but only to Umar personally. According to tradition, in 637 or 638, Caliph Umar traveled to Jerusalem in person to receive the submission of the city. The Patriarch thus surrendered to him.