In the letter,Ts'ao Ts'ao claimed that he had a navy and army combined of 800,000 soldiers.(The actual number was 230,000.) At this point,Liu Pei's Shu Kingdom forces had retreated in defeat to Ch'angpan in Tangyang District,and Sun Ch'uan of Wu Kingdom realized the only way to resist Ts'ao was to form an immediate alliance with Liu Pei.So Sun Ch'uan asked his representative,Lu Su,to visit Liu Pei and discuss the possiblility of an alliance.