About the town of Millbrook:
Cavan and Monaghan Townships were surveyed by John Deyell around 1817 and were named after County Monaghan in Ireland. By 1819 the population of 244 settlers had risen to 4,900 by 1861. Most of the settlers of Irish Protestant descent were United Empire Loyalists and veterans of the War of 1812 obtaining land grants from the Crown. A lot of the Protestants were associated with the Orange Order and in the mid-19th century the famous “Cavan Blazers” were established as ‘a fierce Protestant vigilante group’ that often burned down the farms of Catholic settlers.   Ironically after Confederation in 1867, the population began to drop as settlers headed for Western Canada when the Millbrook Colonization Syndicate was formed to develop land on the Canadian Prairies. Many local farmers moved there because of their marginal farm land in Millbrook Ontario.

The Township of Cavan and the Village of Millbrook became part of Peterborough County in 1974 and were amalgamated, along with North Monaghan into one township. In 2007 the township was once again renamed to Cavan Monaghan to shorten the previous names.