Both
Roman ruins near the church and late-Roman coins at Sonnenhof indicate that the area near Unterkulm was settled during the Roman era. However, Unterkulm is first mentioned in 1045 as
Chulenbare though this is for both Unterkulm and
Oberkulm. In 1303 it was mentioned as
ze Nideren-Kulme which is the first mention of Unterkulm individually. Until 1566 Unter- and Oberkulm formed a
tithe district (), though their political separation was probably earlier. In the 12th and 13th centuries the area was ruled by the Lenzburg family, then the
Kyburgs and finally the
Habsburgs. By 1300 parts of the village were also owned by the monasteries of
Schänis,
Beromünster and
Engelberg as well as local aristocratic families and the
Dukes of Austria. In the 14th and 15th centuries the
Knights Hospitaller houses at
Klingnau and
Biberstein, and the
collegiate church at
Zofingen also became landholders in Unterkulm. After the conquest by
Bern in 1415, Unterkulm remained part of the Court on Kulm in the District () of Lenzburg until 1798. During the
Helvetic Republic (1798–1803) it was a district capital. The village church was built around 1045 and was dedicated to Saint
Martin of Tours. A major
fresco cycle was added in the early 14th century. Its tower houses the oldest clock tower in service (1530), built by the
Winterthur watchmaker Laurentz Liechti. In 1528 the
Protestant Reformation was introduced to the
parish of Kulm. The parish consisted of Unterkulm, Oberkulm,
Teufenthal and
Dürrenäsch, though Dürrenäsch left the parish in 1614. The catholic chapel of Unterkulm is part of the parish of Menziken-Reinach and since 1957 has its own church. In 1565 a school is first mentioned in the village. Towards the middle of the 18th century, in addition to agriculture, cotton spinning and weaving began in the Unterkulm. In the 1780s, out of about 1,000 residents, about 280 people worked in cotton processing. Starting around 1800 the traditional three-field agriculture began to decline, though the dairy industry replaced crop production. In 1893 a dairy company was established in the village. In 1854, a ribbon factory opened and in 1874 a music box factory opened, though that was replaced in 1897 by a now major fittings factory. ==Geography==