Map - Trzin

Trzin ( or ; Tersain ) is a town in the eastern part of the Upper Carniola region of Slovenia. It is the seat of the Municipality of Trzin and also the only settlement in the municipality.

Trzin has a population of 3,922. Its elevation is 299 m above sea level. The town is divided into three parts: the old quarter, Mlake (the new quarter), and the trade-industrial zone. The oldest part of the town is located between Onger Hill to the west and the Mengeš Basin (Mengeško polje) to the east. Trzin's elementary school, town hall, library, fire station, and the 14th-century St. Florian's Church, as well as a number of farms, are all in this part of the town.

Mlake, which is located on the west side of Onger Hill, has banks, a preschool, a leisure centre, and several pubs. It was built on a former swamp. The trade and industrial zone is the newest part of Trzin, built in 1985.

The Slovene politician and journalist Ivan Hribar was born in Trzin.

The oldest preserved document to mention Trzin is dated 15 May 1273. The document is a confirmation by the Carniolan state governor that a certain Vilijem Svibenjki yielded rights to six farms in Trzin on the behalf of the German nobility; the town is mentioned under the name of Direzin. Later documents refer to the town as Terzzein, Terzeyn, Trezein, and Tersein.

Roman archaeological excavations testify to Roman settlements because the Roman road from Emona to Celeia led through Trzin. A local quarry has yielded a Neolithic stone hatchet, which proves the presence of a permanent settlement of this area.

Johann Weikhard von Valvasor described the inhabitants of Trzin as being renowned for making excellent beds, fishing nets, fishing rods and ropes, although they were mostly stock farmers. The local sausage makers are supposedly the "inventors" of Carniola sausage (Kranjska klobasa).

Together with inhabitants of Mengeš and Goričice, the people of Trzin defeated the Turks on Mengeš Field. On 8 September 1813, they fought with Napoleon's Austrian soldiers on Mengeš Field, attacking the 7,000 Frenchmen led by General Belotti.

During the French annexation, brigands flourished in the area, some staying after the French forces had pulled back. According to a well-known story, the most famous brigand, Dimež (Franc Sicherl) and his accomplice Pepelnak (Matijc Mlakar), were killed by the smoke of Trzin's brickyard, on 20 January 1862.

Men from Trzin fought in World War I on the northern border under Rudolf Maister. Eleven men from Trzin fell and four were recorded as missing. During World War I, a nearby airport was used as a base for thirty-two airplanes. During World War II, 25 townsfolk were killed, three died as hostages, five other inhabitants died in internment, and 79 were evicted from their homes.