This policy of artificially isolating the Manchus of the northeast from the rest of China could not last forever. In the 1850s, large numbers of Manchu bannermen were sent to central China to fight the Taiping rebels. (For example, just the Heilongjiang province – which at the time included only the northern part of today's Heilongjiang – contributed 67,730 bannermen to the campaign, of whom only 10–20% survived).Those few who returned were demoralized and often disposed to opium addiction. In 1860, in the aftermath of the loss of "Outer Manchuria", and with the imperial and provincial governments in deep financial trouble, parts of Manchuria became officially open to Chinese settlement; within a few decades, the Manchus became a minority in most of Manchuria's districts.