The town has existed since the Middle Ages and the first written evidence about it is from 1217. From 1348 to 1350 the town remained loyal to the Wittelsbach Louis V the legitimate Margrave of Brandenburg since 1323 against the revolt of the False Waldemar. This event was the origin of the town's name "true" or "faithful" Brietzen. During the Reformation, Martin Luther came in 1537 to preach in the town, but his way to the church was blocked. He preached instead under a basswood, or lime tree, which is called to this day the Lutherlinde.
After the opening of the Sachsenhausen concentration camp in 1936, a sub-camp was opened in the town, where slave labourers were forced to work in a weapons plant. With the approach of the Red Army, on April 23, 1945, the Wehrmacht executed 127 ItalianPOWs, who were interned in the camp. Between April 24 and May 1, 1945, the region was the scene of the Battle of Halbe between the Wehrmacht and the Red Army.
The town was first occupied by the 5th Guards Mechanised Corps on April 21, 1945 but German Wehrmacht and Waffen SS troops managed to return for a short time, finally retreating on April 23. Subsequently Red Army soldiers murdered an estimated 1000 civilian inhabitants of the town during the last days of April and early days of May in a nearby forest. In addition many women were raped. Relatives registered some 251 deaths with the municipal register office, while eyewitnesses, ordered to bury the victims at the local cemetery, stopped counting after they had buried 721 dead, today 125 known graves exist.
The town suffered considerable damage during the war, although the historic town centre remained intact. Since 1945, the town's economy has been concentrated on cattle farming. In 2005, it had 8,548 residents. The mayor of Treuenbrietzen is Michael Knape, of the Treuenbrietzener Bürgerverein (Treuenbrietzen Civic Association).
Development of Population since 1875 within the Current Boundaries (Blue Line: Population; Dotted Line: Comparison to Population Development of Brandenburg state; Grey Background: Time of Nazi rule; Red Background: Time of Communist rule)
Recent Population Development (Blue Line) and Forecasts
Population development within the current boundaries (2013)