Korea independent. He initiated the Gwangmu Reform, which sought to improve the military, industry, and education, to some amount of success. These reforms were seen as insufficient by some parts of the Korean literati, especially the Independence Club, which Gojong at first tolerated but eventually abolished in 1898. After Japan defeated China in the 1894–1895 First Sino-Japanese War, China lost its suzerainty over Korea, which it had held for centuries. In 1897, shortly after returning from his internal exile in the Russian legation in Seoul, Gojong proclaimed the establishment of the independent Korean Empire, and became its first emperor. Gojong's actions drew the ire of Japan. After Japan defeated Russia in the 1904–1905 Russo-Japanese War, it finally became the sole power in the region, and accelerated its pace of absorbing Korea. Two months after the victory, Korea under Gojong lost diplomatic sovereignty in the Japan–Korea Treaty of 1905, signed by five ministers of Korea. Gojong refused to sign it and made attempts to bring the treaty to the attention of the international community and convince leading powers of the treaty's illegitimacy, but to no avail. Gojong was forced to abdicate by Japan on July 20, 1907, and was replaced by his son, Yi Cheok. He was then confined to Deoksu Palace. He made multiple attempts to escape and establish a government in exile abroad, but was unsuccessful each time. Korea formally became a Japanese colony in 1910, and the Korean imperial family was formally absorbed into the Japanese.[clarification needed] Gojong died on January 21, 1919, in his palace, in conditions that were then and are still seen in Korea as suspicious. The official cause of death was cerebral hemorrhage but rumors persisted that Gojong had been poisoned by Japan. His death was a direct catalyst for the March 1st Movement, which in turn bolstered the Korean independence movement.