Mikkeli was the site for the headquarters of the Finnish armed forces during World War II. In recognition of this, the town's coat of arms incorporates a pair of crossed Marshal's batons, and the town was awarded the Cross of Liberty, 4th class, to be displayed with the coat of arms.
The peace treaty of Nöteborg in 1323, with which the Pogosta (church parish) of Savilahti was transferred from the control of Novgorod to Sweden, is the oldest written record of the settlement in the present region of Mikkeli. The locality received its present name Mikkeli after Archangel Michael by the early 16th century at the latest.
On January 23, 1597, more than 200 peasant rebels were killed in the parsonage of Kenkävero in part of the larger Cudgel War. In the war waged by King Gustav III of Sweden against Russia 1788–1790, a battle took place at Porrassalmi Strait, a few miles south of Mikkeli. On June 13, 1789. In the battle the Swedes (the Finns) victoriously defended their positions against superior numbers of Russians.
Mikkeli was granted town rights in 1838. The provincial government of the province of Mikkeli that had been established in 1831, moved from Heinola to Mikkeli in 1843.
In 1918 during the Civil War, the headquarters of the White Army were established in Mikkeli. Mikkeli was located in a conservative farming area and it was a White stronghold. But elements of the Russian army garrison in the area supported the Reds. A major engagement was fought around the railway station at Mantyharju, about 20 km (12 mi) to the south of Mikkeli, when the Whites blocked a Red thrust coming north out of Kouvola. During the Winter War and Continuation War, the headquarters of the Finnish Army was located in Mikkeli. The Army staff made their base in a local secondary school. At the site of that school is the small Headquarters Museum (Päämajamuseo) containing photographs and memorabilia of the era. Because the headquarters of the army was based there, Mikkeli was bombed heavily. But since there was almost no "high-rise" development at that time, the damage was quickly repaired. Architecturally most of prewar Mikkeli doesn't exist anymore.
Wartime Mikkeli is identified with Marshal Mannerheim, the commander of the Finnish army and later President of Finland. His personal railway carriage, which he used as a command post during the war, is parked in a siding at Mikkeli station. It is possible to look inside the carriage through its windows at any time. But public entry to the carriage is only permitted once a year, on Mannerheim's birthday (June 4). The carriage was the venue of Mannerheim's famous 1942 meeting (near Immola) with Hitler, on which occasion a private conversation between the two men was secretly recorded. Photographs of this meeting are on display in the carriage. Mannerheim was a regular diner at the Mikkelin Klubi, where his favourite drink was schnapps. One of the main museums in the town is the Infantry Museum (Jalkaväkimuseo) located in one of the former army barracks, close to the University of Applied Sciences. It contains exhibits from the four wars in Finland's modern history – the Civil, Winter, Continuation and Lapland Wars. The museum also contains an exhibit dedicated to Finnish war hero Lauri Törni.
In 1986, there was a hostage crisis in Mikkeli, when a bank robber drove from Helsinki to Mikkeli with three hostages and parked there. When the police shot at the hostage taker's car, he exploded the car, killing himself and one hostage.
In 1997 there was a province reform, which made Mikkeli the capital of the new province of Eastern Finland. In a separate reform, the rural municipality of Mikkeli which had surrounded the town and the municipality of Anttola were consolidated to Mikkeli in the beginning of the year 2001. The municipality of Haukivuori was consolidated with Mikkeli on January 1, 2007.
The centre of Mikkeli is located on a low rise, near the shore of a bay of Lake Saimaa. There are several small lakes in and around the town. The lakes of the eastern parts of the town belong to the water system of River Vuoksi. In the west the town reaches Lake Puula that belongs to the water system of River Kymijoki.
The municipality has a population of 54,606 (31 March 2016) (around 34,000 in the town itself) and covers an area of 2,548.46 square kilometres (983.97 sq mi) of which 424.7 km2 (164.0 sq mi) is water. The population density is 32.12 inhabitants per square kilometre (83.2/sq mi) .
The municipality is unilingually Finnish (only 0.15% of Mikkelians speak Swedish as their first language).
In 1965, the town was selected as the site for a new higher education college specialising in professional, engineering and vocational studies. Polytechnic received its first intake of students in 1969. It was originally housed in an old Russian army barracks on the outskirts of town. Purpose built accommodation has since been added, but the old buildings are still in use. For example, the student union is located in the "Officers' Club" building. The Polytechnic changed its name to Mikkeli University of Applied Sciences in 2006 and currently receives around 4,500 students each year from around the world. (Hence, the name has not been approved by the Finnish Ministry of Education.) Its International Studies Centre runs business, engineering and IT courses delivered in English. It offers some degree programmes which are wholly delivered in English. but the University of Applied Sciences's main language of delivery is Finnish.
Several other universities also have operations in Mikkeli. The Mikkeli University Consortium includes units from University of Helsinki, Aalto University (formerly Helsinki School of Economics), University of Eastern Finland and Lappeenranta University of Technology. Aalto offers a highly ranked Bachelor of Science degree in international business, taught in English, which draws students and faculty from around the world.
Mikkeli has its own airport (domestic flights only), railway station (five trains to and from Helsinki, daily) and a concert hall. The latter is a genuinely world class facility, built in 1988 to commemorate Mikkeli's 150th anniversary as a town. The concert hall is the home of St. Michel Strings chamber orchestra, and also provides the main venue for the annual Mikkeli International Music Festival, which attracts musicians and audiences from across Europe. For example, Mariinsky Opera led by Valery Gergiev performs there regularly. The University of Applied Sciences is now the largest single employer in the town. It employs around 400 full-time teaching staff plus around 900 support and services staff. Other local employers operate in the forestry, paper, printing, farming and light manufacturing sectors. The Mikpoli complex houses many local companies. Mikkeli is also a major holiday resort within the Finnish lakeland area.
Jukurit is an ice hockey team in Mikkeli. The team has won six Mestis's championships (2001, 2002, 2003, 2006, 2013 and 2015).
Mikkelin Kampparit, or just Kampparit, plays in the highest bandy division. In 2012, they became Finnish champions for the first time.
The local football team is the First Division Mikkelin Palloilijat (MP). Olli Rehn used to play there for 13 years (youth teams 1968–78, first team 1979–82).Jalo Autonen
Mikkeli is twinned with: