Task: Question Generation
Input (English): The Western powers, largely unsatisfied with the Treaty of Nanjing, gave grudging support to the Qing government during the Taiping and Nian Rebellions. China's income fell sharply during the wars as vast areas of farmland were destroyed, millions of lives were lost, and countless armies were raised and equipped to fight the rebels. In 1854, Britain tried to re-negotiate the Treaty of Nanjing, inserting clauses allowing British commercial access to Chinese rivers and the creation of a permanent British embassy at Beijing.
Output (English): When did the British try to redo the Treaty of Nanjing?