 August 1793: Lord McCartneys British delegation on its way to the imperial capital Peking is amazed to discover the Great Wall, and by their Chinese escort s utter indifference about it. The present wall was build under the Ming dynasty. In 1541 the sinified Mongolian ruler Altan Khan who has established a capital in Chinese fashion asks to establish trade, but after the emperor has his delegation executed the nomads invade and devastate; a new commanding general was ordered to assure the empires northwestern defense by building a long wall along nine pre-existing forts, partially renewing a 1000 AD wall, with advanced observation posts. In 1550 the Khan s first major attack with 30,000 men is halted, but he promises to get to Peking and another attack at a small pass allows him so, yet his terms are only trade relations, which are soon broken off again while the Great Wall is gradually elaborated, over 4000 kilometer along the Ming empires northern borders. The army and even more commandeered rural workers were used, at extreme expense in material, effort and victims during 90 years, corruption still increases the financial cost; the garrisons are substandard. In 1644 a farmers revolt reaches Peking, where the Ming emperor hangs himself, general Li seizes the throne. The Manchu nomads are let in by the last loyal general and found a new imperial dynasty, the Ching.