The establishment of permanent settlement in what is now Hausjärvi is presumed to have begun around the 1300s by hunters from Janakkala. The first estates in Hausjärvi sprung up around river Puujoki, and the inhabitants were known to practice hunting as well as slash-and-burn agriculture. Metsäkansa - as Hausjärvi was known in the era around and preceding the Greater Wrath - was made a distinct chapel parish of the mother parish of Janakkala in 1611, which also prompted the construction of its first church in the same year. Hausjärvi was elevated to the status of an independent parish by imperial proclamation in 1855.