(1925) Heimberg is first mentioned in 1146 as
Heimberc. The oldest trace of a settlement in the area are the
Roman settlement ruins near Bühlacker. By the
Middle Ages the village existed and was ruled by the
Freiherr von Heimberg. Very little is known about the family. They appear in historical records from 1146 until 1175 and then vanish. By 1191 the
Zähringens owned the village. It was later divided and inherited by the
Counts of Kyburg and the Counts of
Buchegg. In 1259 Buchegg donated their portion to
Interlaken Monastery but the Kyburgs retained their half ownership and, apparently, full control over the village. After a failed raid on
Solothurn on 11 November 1382 and the resulting
Burgdorferkrieg, the Kyburgs lost most of their lands to
Bern in 1384. The city of Bern then passed the half portion of the village to the Bernese
Schultheiss Ludwig von Seftigen to rule as a private dominion within the
Steffisburg court under the
Thun District. Presumably after the 1528 conversion of Bern to the new faith of the
Protestant Reformation and suppression of Interlaken Monastery, the two halves of the village were combined. The village passed through a number of Bernese
patrician families over the following centuries. The village was part of the
parish of
Thun until 1536, when it became part of the Steffisburg parish. For most of its history Heimberg consisted of scattered farm houses in the floodplains of the
Aare, Zulg and Rotache rivers. The swampy valley floors provided rich soil but very limited space. The Aare River Correction projects of 1871-76 constrained the river and drained the marshy lands on the valley floor, which opened up new housing and farm land. At around the same time the construction of the Bern-Thun road and the
Burgdorf-Thun railroad connected the village with several nearby cities. The road and navigable Aare river brought about 80 import/export and transport companies to Heimberg in the mid-19th century. When it began to decline in the 1870s, the growing municipality began supporting industry in Thun. After World War II the population of Heimberg expanded rapidly and new developments sprang up around the old village, including Hubel-Bäumberg and Kaliforni as well as the Winterhalde industrial park. A school was built in Au in 1953-56 and replaced in 1975–86, and followed by a secondary school in 1981. The village church was built in 1939, followed by a second church in Kaliforni in 1979. Heimberg split away from the Steffisburg parish to form its own parish in 1988. ==Geography==