The old mountain town Suhl has had an eventful history. Already since 500 B.C. Celtic tribes settled in this region. These early settlers were looking for iron ore to process pure iron. Records from the years 900 and 1155 of the convent of Fulda mention a settlement called "Sulaha". Since around 1100 the area is owned by the Count of Henneberg. In the year 1318 the town was mentioned in documents for the first time. From the year 1365 on two forge hammers can be proved and in 1437 another "schluttgarten zu sula" followed. At that time the production of weapons and armament was already in progress. A court for miners already existed since 1470. In 1527 the Count of Henneberg approved the so called town privileges. It is proved that Suhl received its town charter that year.
Already since 1500 firearms have been produced in Suhl. Documents show that there were about 800 miners at that time. Documents from the guild of smiths can be proved from the year 1555. In 1631 "Europe's armoury" already had 7000 citizens. However the selling of weapons to friends and enemies also caused major destructions of the town in times of war. For example on St. Gall's Day (16 October) 1634 during the Thirty Years War the imperial troops of the Croatian General Isolani put the town to ashes. Fires in the town devastated large parts of the settlement (1509, 1580 and 1753).
In 1718 the territory was owned by "Kursachsen"(Electoral Saxony). For the time being mining and arms trade declined. Fustian weaving and the art of gun making developed instead. Precious pieces of this artistry from Suhl's master craftsmen, for example Stockmar can nowadays be seen in the museum "Grünes Gewölbe" in Dresden. Thus the production of arms in Suhl also caused the town to prosper. 1751 is the year when "Sauer & Sohn" was founded. This was the first German gun factory and after the one in Liege (Belgium) the second in Europe. Between 1756 and 1760 Suhl's gunsmiths sold 25,000 rifles to Prussia. Because of this standing the town as well as the whole county of Henneberg joined the Kingdom of Prussia.
In the 19th century Suhl experienced a boom because of beginning industrial- ization. The "Haenel" arms and cycle factory was founded in 1840. The famous Simson factory, which produced arms and vehicles, followed in 1856. The "Schlegelmilch" porcelain factory commenced production in 1861. In 1884 Suhl got connected to the railroad system. Around 1900 the town had 13,000 citizens. During Word War I about 12,000 employees from the region worked for the Suhl armaments industry. At the end of the war the situation of many citizens worsened rapidly. The Kapp Putsch, inflation and the world economic crisis characterized the twenties and the beginning of the thirties of the 20th century. In the times of preparation and during World War II Suhl again supplied weaponry. Primarily at the "Gustloff" plant, which was formed by the national socialists from the expropriated Simson plant, pistols, assault rifles and machineguns were produced. More than 10,000 forced labourers worked in factories of military importance. The town had about 25,000 citizens. On 3 April 1945 American troops occupied Suhl and ended the national socialist regime. During combats prior to this, lots of houses burned down. In 1945 after the Soviet occupation began many factories were nationalized. Companies like "Krieghoff" moved to the western part of Germany.
After the administrative reform in the GDR Suhl was made a district capital on 23 July 1952. At that time Suhl had 24,496 citizens. In the following years Suhl developed rapidly. The construction of new homes - increasingly from prefab panels - and of satellite towns during the 70s and 80s changed the image of the city. For building public as well as prestigious buildings whole parts of the old town were demolished. On 12 May 1967 the town was given the status of a non-district (independent) city.
In November/December 1989 a social turning point was reached as numerous demonstrations and the occupation of the Stasi (security service) headquarters took place. On 6 May 1990 the citizens of Suhl were able to elect their town assembly for the first time again since 1950 in free elections. Extensive restructuring projects were started. The former compound of the GDR Border Guards College became the new business park Friedberg - the biggest business park of the region.
The former municipal hall including its surrounding was renovated and became the new Congress Centre Suhl (opened to the public on 2 December1995). The construction of the Lauterbogen shopping centre in 1996 as well as since 1998 the reconstruction of the shopping street Steinweg and the market square continued the development of the inner city. From 1999 until 2007 a completely new Federal autobahn A71/A73 with three exits to Suhl and the junction on the town's territory was built.