Nader Shah dreamed of an empire which would stretch from the Indus to the Bosphorus. Therefore he raised an army of 200,000, which consisted largely of rebellious Central Asian tribesmen, and he planned to march towards Constantinople, but after he learned that the Ottoman ulema was preparing for a holy war against Persia, he turned eastward. He captured Kirkuk, Arbil and besieged Mosul on 14 September 1743. The siege lasted for 40 days. The Pasha of Mosul, Hajji Hossein Al Jalili, successfully defended Mosul and Nader Shah was forced to retreat. The offensive was halted due to revolts in Persia  over high taxes. Hostilities also spilled into Georgia, where Prince Givi Amilakhvari employed an Ottoman force in a futile attempt to undermine the Persian influence and dislodge Nader's Georgian allies, Princes Teimuraz and Erekle. In early 1744 Nader Shah resumed his offensive and besieged Kars, but returned to Daghestan to suppress a revolt. He returned afterwards and routed an Ottoman army at the battle of Kars in August 1745. The war disintegrated. Nader Shah grew insane and started to punish his own subjects, which led to a revolt from early 1745 to June 1746. In 1746 peace was made. The boundaries were unchanged and Baghdad remained in Ottoman hands. Nader Shah dropped his demand for Ja'fari recognition. The Porte was pleased and dispatched an ambassador but before he could arrive, Nader Shah was assassinated by his own officers.
Question: What happened first, the capture of Kirkuk or the defense of Mosul?
Answer: captured Kirkuk