Although much of Wang Anshi's reforms outlined in the New Policies centered on state finance, land tax reform, and the Imperial examinations, there were also military concerns. This included policies of raising militias to lessen the expense of upholding a million soldiers, putting government monopolies on saltpetre and sulphur production and distribution in 1076 (to ensure that gunpowder solutions would not fall into the hands of enemies), and aggressive military policy towards Song's northern rivals of the Western Xia and Liao dynasties. A few years after Song Dynasty military forces had made victorious territorial gains against the Tanguts of the Western Xia, in 1080 Shen Kuo was entrusted as a military officer in defense of Yanzhou (modern-day Yan'an, Shaanxi province). During the autumn months of 1081, Shen was successful in defending Song Dynasty territory while capturing several fortified towns of the Western Xia. The Emperor Shenzong of Song rewarded Shen with numerous titles for his merit in these battles, and in the sixteen months of Shen's military campaign, he received 273 letters from the Emperor. However, Emperor Shenzong trusted an arrogant military officer who disobeyed the emperor and Shen's proposal for strategic fortifications, instead fortifying what Shen considered useless strategic locations. Furthermore, this officer expelled Shen from his commanding post at the main citadel, so as to deny him any glory in chance of victory. The result of this was nearly catastrophic, as the forces of the arrogant officer were decimated; Xinzhong Yao states that the death toll was 60,000. Nonetheless, Shen was successful in defending his fortifications and the only possible Tangut invasion-route to Yanzhou.