After Landing at Fao and taking the old fortress of Basra, the British planned their next move to secure the oil fields of Abadan. The decided to move further inland.
Meanwhile, the Ottomans had only retreated strategically, and built themselves a defensive position at Qurna, where the Tigris and Euphrates rivers meet. The move made sense because the British would have to cross one or both of the rivers, and by controlling their meeting point, the Ottomans forced either a battle on their terms or a long detour by the British.
Upon their arrival near Qurna, the British forces mustered about 2,100 men, and the Ottomans about 1,000.
The British successfuly stormed the Ottoman defenses, but found that they lacked a means to cross the river which the Ottomans holding the other bank as well, and retreated. After reorganizing, they stormed the same Ottoman defenses (the Ottomans had re-occupied them) and again drove them off only admit again that they could not find a way to cross the river.
Finally, a detachment was sent Further upstream to cross the river than thus descend upon the Ottomans from the rear. Now beset on all sides, the Ottomans eventually surrendered.