History: Central Asia, 140 Years Ago

The idea of Central Asia as a distinct region of the world was introduced in 1843 by the geographer Alexander von Humboldt. The borders of Central Asia are subject to multiple definitions.
The most limited definition was the official one of the Soviet Union, which defined Middle Asia as consisting solely of Uzbekistan, Turkmenistan, Tajikistan and Kyrgyzstan. This definition was also often used outside the USSR during this period.
However, the Russian culture has two distinct terms: Средняя Азия (Srednjaja Azija or "Middle Asia", the narrower definition, which includes only those traditionally non-Slavic, Central Asian lands that were incorporated within those borders of historical Russia) and Центральная Азия (Central'naja Azija or "Central Asia", the wider definition, which includes Central Asian lands that have never been part of historical Russia).
Soon after independence, the leaders of the four former Soviet Central Asian Republics met in Tashkent and declared that the definition of Central Asia should include Kazakhstan as well as the original four included by the Soviets. Since then, this has become the most common definition of Central Asia.