On 1 August 1860, as an attaché to General Sir James Grant, Parkes was sent to Pehtang, Tientsin to take possession of the evacuated fort and perform some reconnaissance during the advance to the Taku Forts. After the successful assault on the main north fort on 21 August, he assisted in the negotiations for the surrender of the remaining Chinese positions in the forts. Three days later, he arrived in Tientsin, where he arranged for provisions for the Anglo-French forces and had meetings with the Qing imperial commissioners. Upon learning that the imperial commissioners did not hold plenipotentiary powers from the Xianfeng Emperor as they initially believed, the British and French troops then advanced further towards Tungchow near the Qing capital, Peking.