Conscription in the Russian Empire was introduced by Peter I of Russia. The conscripts to the Imperial Russian Army were called "recruits" in Russia (not to be confused with voluntary recruitment), which did not appear until the early 20th century. The system was called "recruit obligation". The term of service in 18th century was for life. In 1793 it was reduced to 25 years. In 1834 it was reduced to 20 years plus 5 years in reserve and in 1855 to 12 years plus 3 years of reserve. Only sons were not regularly conscripted to the army.