Rubuta ci gaba don wannan sakin layi - Daga baya Khalid ya yi yaƙi da kabilun Larabawa da yawa na Krista da kuma sansanin sojojin Farisa na Sasanian na kwarin Euphrates a Iraki. Abu Bakr ya sake sanya shi ya jagoranci sojojin musulmai a Siriya kuma ya jagoranci mutanensa a can a kan wani tafiya mai ban mamaki a kan wani dogon lokaci, wanda ba shi da ruwa a cikin hamada na Siriya, yana karfafa sunansa a matsayin mai tsara tsarin soja. Sakamakon gagarumar nasara a kan Byzantines a Ajnadayn (634), Fahl (634), Damascus
(634<unk>635) da Yarmouk (636), Musulmai a ƙarƙashin Khalid sun ci yawancin Siriya. Daga baya Umar ya sauke shi daga babban kwamandan saboda wasu dalilai da aka ambata ta hanyar al'adun Islama da na zamani. Khalid ya ci gaba da aiki a matsayin babban mataimakin magajinsa Abu Ubayda ibn al-Jarrah a cikin kewaye da Homs da Aleppo da yakin Qinnasrin, duk a cikin 637<unk>638, wanda gaba ɗaya ya sa aka janye daga Siriya na sojojin Byzantine na daular a ƙarƙashin Sarkin sarakuna Heraclius. Umar ya kori Khalid daga gwamnatinsa na Qinnasrin bayan haka kuma ya mutu a Madina ko Homs a 642.