Mari El, officially the Mari El Republic, is a republic of Russia. It is in the European region of the country, along the northern bank of the Volga River, and administratively part of the Volga Federal District. The republic has a population of 696,459 (2010 Census). Yoshkar-Ola is the capital and largest city.

Mari El, one of Russia's ethnic republics, was established for the indigenous Mari people, a Finno-Ugric nation who have traditionally lived along the Volga and Kama Rivers. The majority of the republic's population are ethnic Russians (52.5%), with a significant Mari minority (40.1%), and smaller minority populations of Tatars and Chuvash. The official languages are Russian and Mari. Mari El is bordered by Nizhny Novgorod Oblast to the west, Kirov Oblast to the north, Tatarstan to the east, and Chuvashia to the south.

The Republic is located in the eastern part of the East European Plain of Russia, along and mostly to the north of the Volga River. The swampy Mari Depression is in the west of the Republic, contrasted by hillier landscapes in the east where the highest point of the Republic (at 278 metres (912 ft)) is located. The Republic borders with Kirov Oblast in the north and east, the Republic of Tatarstan in the southeast and south, the Chuvash Republic in the south, and with Nizhny Novgorod Oblast in the west and north.^{[citation needed]}

There are 476 rivers in the Republic, with the Volga and its tributaries being the major water arteries. Most rivers are considered to be minor—10–50 m (33–164 ft) wide and 0.5–1.4 m (1 ft 8 in – 4 ft 7 in) deep—and usually freeze between mid-November and mid-April. There are over 700 lakes and ponds; many located in the swampy areas and have areas of less than 1 km² (0.39 sq mi) and depths of 1–3 m (3 ft 3 in – 9 ft 10 in). Lake Yalchik, occupying 150 hectares (370 acres), is the largest by area, while Lake Tabashinskoye is the deepest. Swamps cover large areas—10–70 km² (3.9–27.0 sq mi) and up to 100 km² (39 sq mi)—and usually freeze in December. While swamps tend to be shallow, with an average depth of 0.5–1.5 m (1 ft 8 in – 4 ft 11 in), they are impassable in fall and spring due to flooding.^{[citation needed]}

Climate is moderately continental, with moderately cold and snowy winters and warm and often rainy summers. The average temperatures range from 18–20 °C (64–68 °F) in summer to −18 – −20 °C (0 – −4 °F) in winter. November is the windiest month of the year. Annual precipitation varies from 450 to 500 mm (18 to 20 in).

There are virtually no natural resources of industrial significance in the Republic. Other resources include peat, mineral waters, and limestone. About 50% of the Republic's territory is forested, although the level of forestation varies significantly from one district to another.^{[citation needed]}

Ancient Mari tribes were known since the 5th century, though archaeologists suspect that the Mari culture is much older in its roots. Later their area was a tributary of Volga Bulgaria and the Golden Horde. In the 1440s it was incorporated into the Khanate of Kazan and was occupied by the Tsardom of Russia (governed by Ivan the Terrible) after the fall of Kazan in 1552.

After the Russian Revolution, under the Bolshevik regime, the Mari Autonomous Oblast was established on 4 November 1920. It was re-organized into the Mari ASSR on 5 December 1936, at the same time as the enactment of the 1936 Soviet Constitution. In its present form, the Mari El Republic was formed on 22 December 1990. On 21 May 1998, Mari El alongside Amur, Ivanovo, Kostroma, and Voronezh Oblast signed a power-sharing agreement with the federal government, granting it autonomy. This agreement was abolished on 31 December 2001.