In the late 19th century, China adopted the Western model of nation-state diplomacy. As the government of Tibet, China concluded several treaties (1876, 1886, 1890, 1893) with the British Indian government touching on the status, boundaries and access to Tibet. Chinese government sources consider this a sign of sovereignty rather than suzerainty. However, by the 20th century British India found the treaties to be ineffective due to China's weakened control over the Tibetan local government. A British expeditionary force invaded Tibet in 1904 and mandated the signing of a separate treaty, directly with the Tibetan government in Lhasa. In 1906, an Anglo-Chinese Convention was signed at Peking between Great Britain and China. It incorporated the 1904 Lhasa Convention (with modification), which was attached as Annex. A treaty between Britain and Russia followed in 1907. Article II of this treaty stated that "In conformity with the admitted principle of the suzerainty of China over Tibet, Great Britain and Russia engage not to enter into negotiations with Tibet except through the intermediary of the Chinese Government." China sent troops into Tibet in 1908. The result of the policy of both Great Britain and Russia has been the virtual annexation of Tibet by China. China controlled Tibet up to 1912. Thereafter, Tibet entered the period described commonly as "de facto" independence, though it was only recognized by independent Mongolia as enjoying "de jure" independence.