The first occupants of the area where Ulan-Ude now stands were the
Evenks and, later, the
Buryat Mongols. Ulan-Ude was settled in 1666 by the Russian
Cossacks as the fortress of Udinskoye. Due to its favorable geographical position, it grew rapidly and became a large trade center which connected Russia with
China and
Mongolia and, from 1690, was the administrative center of the
Transbaikal region. By 1775, it was known as Udinsk, and in 1783 it was granted city status and renamed Verkhneudinsk. After a large fire in 1878, the city was almost completely rebuilt. The
Trans-Siberian Railway reached the city in 1900 causing an explosion in growth. The population, which was 3,500 in 1880, reached 126,000 in 1939. From 6 April to October 1920,
Verkhneudinsk was the capital of the
Far Eastern Republic, also known as the Chita Republic. It was a nominally independent state that existed from April 1920 to November 1922 in the easternmost part of the
Russian Far East. On 27 July 1934, the city was renamed Ulan-Ude. Following the
dissolution of the
Soviet Union, a period of rapid and uncontrolled illegal construction of private houses on officially designated agricultural land began. This phenomenon became known as
Nakhalovki. Due to the deteriorating economic situation in the region, the city of Ulan-Ude emerged as a favourable destination for internal migration. However, the growing population was met with a supply of formal housing which was not enough to accommodate the growth of the city population, which in turn fuelled the spread of Nakhalovki districts in the city suburbs. The uncontrolled growth of those districts makes them suffer from lack of necessary infrastructure. ==Administrative and municipal status==