the Assam Duars and Bengal Duars, which were the most fertile part of Bhutan in those days. For economic reason, and to secure the borders of their empire, the British attempted to extend their boundaries up to the foothills of Bhutan. The Assam Duars were annexed in 1841 although a formal treaty ceding it did not take place until 1865. In 1864, the British unilaterally declared that, in addition to the Assam Duars that were already annexed, the Bengal Duars would be annexed permanently. Following this, the British sent forces to occupy vital passes into Bhutan such as Deothang, Sidli and Buxa. Jigme Namgyal launched a counter offensive with about 5000 men and succeeded in dislodging the British Imperial Force at Deothang. He was successful in the January and February 1865 attacks on the British outpost in Deothang. However, later that year Bhutan was forced to sign the Treaty of Sinchula, 1865. The treaty brought stability to the relationship between the two countries. The Duars were incorporated permanently into the British Empire and an annual subsidy of Rs 50,000 to Bhutan was instituted from that year. Three legacies of Desi Jigme Namgyal The most important contribution of Desi Jigme Namgyal made was the ushering in of peace, through a reduction of local feuds among the top leadership by gradually unifying the state over three decades, from the 1850s to 1870s. The reduction of internal conflicts, especially after 1878, allowed for laying the foundation of the monarchy that in turn brought a peaceful era in Bhutan. In terms of external relationship, especially with British India, Desi Jigme Namgyal left an identifiable centre of power that made it possible for treaties to be revised constructively and foreign relationships to be improved over the course of time. His son, the first King of Bhutan, Ugyen Wangchuck amply fulfilled that role later on. After Jigme Namgyal's reign, foreign relations could be conducted in a systematic and co-ordinated way, because the fragmentation of power among the top leadership could be avoided. The Treaty of Sinchula, 1865, which went back to Jigme Namgyal's time, became the crucial, guiding bilateral legal instrument between Bhutan and British India and later, Independent India. It was updated and revised in 1910, 1949, and 2007. Jigme Namgyel made not only political but architectural impacts. He restored the Tongsa Dzong, and built Sangwa Duepa temple in it. He founded the Wangducholing Palace