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Lieutenant general (Lt Gen, LTG and similar) is a usually three-star military rank used in many countries. The rank traces its origins to the Middle Ages, where the title of lieutenant general was held by the second-in-command on the battlefield, who was normally subordinate to a captain general.
In modern armies, lieutenant general normally ranks immediately below general (or colonel general) and above major general; it is equivalent to the navy rank of vice admiral, and in air forces with a separate rank structure, it is equivalent to air marshal. A lieutenant general commands an army corps, made up of typically three army divisions, and consisting of around 60 000 to 70 000 soldiers (U.S.).
The seeming incongruity that a lieutenant general outranks a major general (whereas a major outranks a lieutenant) is due to the derivation of major general from sergeant major general, which was a rank subordinate to lieutenant general (as a lieutenant outranks a sergeant major). Several countries (e.g. Balkan states) use the rank of lieutenant colonel general instead of lieutenant general, in an attempt to solve this apparent anomaly.
In contrast, in Russia and a number of other countries of the former Soviet Union, lieutenant general is a two-star rank, immediately below colonel general, and above major general – in these systems this last rank has one star, without any use of the brigadier general of many Western countries.
However, some countries of South America (such as Brazil and Chile) use divisional general as the equivalent of lieutenant general. In addition, because no brigadier general rank is used in Japan and Taiwan, lieutenant general is the rank of divisional commander. Therefore, it corresponds to divisional general of these countries. In a number of smaller states which employ NATO and western style military organisational structures, because of the limited number of soldiers in their armies, the rank of lieutenant general is the highest army rank in use. In Latvia, Lithuania, and Singapore, the chief of defence is a lieutenant general, and in the Irish Defence Forces and Israel Defence Forces, the Chief of Staff holds this rank.