Sophie Mannerheim Jr. - Officer in The Imperial Russian Army

Officer in The Imperial Russian Army

At the end of July 1887, Mannerheim was informed that he could take the entrance examination of the Nicolas Cavalry School in St. Petersburg. He passed the exam and swore his soldier's oath to the Tsar of Russia on 16 September 1887. Mannerheim graduated in 1889, tenth in his class after falling from second place following a drunken argument about Finnish autonomy with a superior officer. Mannerheim swore to never drink to excess again. Mannerheim was commissioned as a Cornet. He was posted to the 15th Alexandriyski Dragoons at Kalisz on the Russian-German border.

In January 1891, Mannerheim was transferred to Her Majesty's Maria Feodorovna's Chevalier Guard in St Petersburg - a position in which his height (he stood at 187 cm (6' 1½")) was an advantage, and one which also led to his being given a prominent place in the ceremonies for Tsar Nicholas II's coronation in 1896. In 1892, Mannerheim's godmother, Countess Alfhild Scalon de Coligny, arranged for him to be married to a wealthy and beautiful noble lady of Russian-Serbian heritage Anastasia Arapova (1872–1936), the orphaned daughter of Major-General Nikolai Arapov. Mannerheim and she had two daughters, Anastasie (1893–1978) and Sophie (1895–1963); a third child, a son, was stillborn. Anastasie would later convert to Catholicism and become a Carmelite nun in England. Mannerheim separated from Anastasia Arapova in 1902, and they were divorced in 1919.

Mannerheim served in the Imperial Chevalier Guard until 1904, though he was posted to the Imperial Court Stables Administration from 1897 to 1903. Mannerheim specialised as an expert on horses, buying stud stallions and special duty horses for the army. In 1903, he was put in charge of a display squadron and became a member of the equestrian training board of the cavalry regiments.

After Mannerheim's separation from his wife, his financial situation became bleak. This was exacerbated by gambling losses. He became depressed and tried to overcome his depression through a change of environment. Mannerheim volunteered for duty in the Russo-Japanese war in 1904. In October 1904, he was transferred to the 52nd Nezhin Dragoon Regiment in Manchuria, with the rank of Lieutenant-Colonel. He was promoted to Colonel for his bravery in the Battle of Mukden in 1905 and briefly commanded an irregular unit of Hong Huzi local militia on an exploratory mission into Inner Mongolia.

On returning from the war, Mannerheim went on an informal vacation among his relatives in Finland and Sweden 1905–1906. As one of the baronial branch of his family, he was a member of the Estate of Nobility in the last session of the Diet of Finland.

When Mannerheim returned to St. Petersburg, he was asked if he would like to make a journey through Turkestan to Beijing as a secret intelligence-officer. General Palitsyn, Chief of the Russian General Staff, wanted accurate, on-the-ground intelligence about the reform and modernization of the Qing Dynasty. The Russians wanted to know the military feasibility of invading Western China, including the provinces of Xinjiang and Gansu, in their struggles with Britain for control of Inner Asia known as "The Great Game." After much deliberation, Mannerheim, disguised as an ethnographic collector, joined the French archeologist Paul Pelliot's expedition in Samarkand in Russian Turkestan (now Uzbekistan). From the terminus of the Trans-Caspian Railway in Andijan, the expedition started in July 1906, but Mannerheim spent the greater part of the expedition alone, after quarrelling with Pelliot over several logistic issues on their way to Kashgar in China's Xinjiang province.

With a small caravan, including a Cossack guide, Chinese interpreter, and Uyghur cook, Mannerheim first trekked to Khotan in search of British and Japanese spies. Upon returning to Kashgar, he headed north into the Tian Shan range, surveying passes and gauging the attitudes of Kalmyk, Kazakh, and Kyrgyz tribes towards the Han Chinese. Mannerheim arrived in the provincial capital of Urumqi, and then headed east to Turpan, Hami, and Dunhuang in Gansu province. He followed the Great Wall of China through the Hexi Corridor, and investigated a mysterious tribe known as Yugurs. From Lanzhou, the provincial capital, Mannerheim headed south into Tibetan territory and the lamasery of Labrang, where he was stoned by xenophobic monks. He eventually made it to Xi'an, Zhengzhou and Kaifeng in Central China. At Zhengzhou, Mannerheim took a train to Taiyuan, the capital of Shanxi province, and then trekked to the sacred Buddhist mountain of Wutai Shan, where he met the Dalai Lama, who was launching a nascent campaign to free Tibet from Chinese Imperial rule. Mannerheim gave the Tibetan pontiff his own pistol as a gift and for protection against the Chinese. Mannerheim then headed north beyond the Great Wall into steppe traditionally occupied by Mongol herders. He arrived in Hohhot, the capital of Inner Mongolia, and found the Mongols in a rebellious mood because of a corrupt military governor who was colonizing Mongol pasture lands with Han Chinese farmers. Mannerheim eventually arrived in Beijing in July 1908, where he worked on his military intelligence report. He returned to St. Petersburg via Japan and the Trans-Siberian Express. His military report was a detailed account of modernization in the late Qing Dynasty, covering education, military reforms, Han colonization of ethnic borderlands, mining and industry, railway construction, the influence of Japan, and opium smoking. Mannerheim's report outlined the likely tactical uses of a Russian invasion of Xinjiang, and Xinjiang's possible role as a bargaining chip in a putative future war with China.

After Mannerheim's return to Russia in 1909, he was appointed to command the 13th Vladimir Uhlan Regiment at Mińsk Mazowiecki in Poland. The following year, Mannerheim was promoted to Major General and was posted as the commander of the Life Guard Uhlan Regiment of His Majesty in Warsaw. In 1912, Mannerheim became part of the Imperial entourage, and the following year he was appointed cavalry brigade commander.

At the beginning of World War I, Mannerheim served as commander of the Guards Cavalry Brigade, and fought on the Austro-Hungarian and Romanian fronts. After distinguishing himself in combat against the Austro-Hungarian forces, Mannerheim was in December 1914 awarded the Order of St. George, 4th class. He said after receiving this award, "now I can die in peace." In March 1915, Mannerheim was appointed to command the 12th Cavalry Division.

Mannerheim received leave to visit Finland and St. Petersburg in early 1917, and witnessed the outbreak of the February Revolution. After returning to the front, he was promoted to Lieutenant General in April 1917 (the promotion was backdated to February 1915), and took command of the 6th Cavalry Corps in the summer of 1917. However, Mannerheim fell out of favour with the new government, who regarded him as not supporting the revolution. In September he was relieved of his duties, while on sick-leave after having fallen from his horse. He was now in the reserve and trying to recover his health in Odessa. He decided to retire and return to Finland, which he did that December.