the 3rd Cavalry, where he served as commandant of the Cavalry School at Fort Riley until 1898. Spanish–American War With the outbreak of the Spanish–American War in 1898, Chaffee was assigned a brigade and was promoted to brigadier general of volunteers in May of that year, and in July after the victory at El Caney, to major general of volunteers. From late 1898 to May 1900, he served as the chief of staff to the military governor of Cuba, General Leonard Wood, being promoted to colonel of regulars in May 1899. He was a member of Society of the Army of Santiago, a military society for officers who had served in Cuba. Boxer Rebellion In June 1900, the Boxer Rebellion broke out in China. Colonel Chaffee was sent to China in July as the commander of the U.S. Army's China Relief Expedition. The Expedition was a part of the international force sent to rescue Western citizens and put down the rebellion. Chaffee participated in the Gaselee Expedition and subsequently the Battle of Peking, in which the legations were relieved. In 1900-1901 American forces were included in the Allied occupation of Peking (Beijing). As American commander Chaffee began public health, relief, and police operations in cooperation with Chinese officials. Chaffee concluded that Asiatics respected only the superior power. Reassigned to the Philippines he applied the lessons there, combining benevolence and public health measures with force and cooperation with local officials. Chaffee was one of the founders of the Military Order of the Dragon, a military society for officers who had served in China during the Boxer Rebellion. He served as the society's president from its founding in 1900 until his death. Later military service In February 1901, he was promoted to major general in the Regular Army. From July of that year until October 1902, he served as the military governor of the Philippines. This included the beginning of the second phase of the Philippine–American War. In October 1902, he became commander of the Department of the East, a position he held until October 1903. In January 1904, he was promoted to lieutenant general and, from January 9, 1904, until January 14, 1906, served as the Chief of Staff of the United States Army. At his own request, he was retired on February 1, 1906. General Chaffee was invested with the Grand Cross of the Legion of Honor by the president