The inclusion of Jia She’s 賈涉 biography in the History of the Song is usually attributed to the political influence of his son, Jia Sidao 賈似道. This essay, however, argues that Jia She’s inclusion should be credited to his successful handling of border defense, refugee problems and foreign affairs during the turbulent era of the competing Song, Jin and Mongol regimes. By the timely application of Song court policies he consolidated the border regions and recruited the loyalist armies of Shandong, turning them into a major irredentist and emergency force. He also advocated alliance with the Mongols at opportune moments. It was due to his successes that he stood out and managed to flourish even at such an era of political instability. The development of the loyalist armies and the rise to power of Li Quan 李全 had a great impact on Jia She’s career. Jia She had at first employed the tactics of monetary enticement and discord to smoothly manage the loyalist armies. However, with the growth of Li Quan’s power and his separatist ambitions, Jia She was unable to counteract and finally exhausted his resources. Clearly, as Jia She’s policies lacked court recognition and sufficient support, he was no longer able to cope with the urgencies of the situation. Jia She’ s career is the focus of five main sections of this essay. In addition to reassessing and supplementing biographical data, this essay examines the full significance of his historical role by contextualizing Jia She in the historical complexities of the Southern Song. We will thereby have a clearer understanding of the processes of socio-political conflicts and integration in 20th century China.