The first permanent settlement in what is now the town of Ajax occurred around 1801 in a village called Pickering. This is somewhat confusing as today the city directly west of Ajax is also called Pickering, but back then the entire region was known as Pickering Township and the village simply took its name from that. The land around Pickering Village was mostly quiet farmland, and it might have remained so to this day if not for the outbreak of World War II.
In 1941 Defense Industries Limited established the Pickering Works, a shell filling plant which would churn-out over 40 million units of ammunition by the end of the war, right in the middle of this once peaceful countryside. The massive new facility attracted some 9,000 employees from across Canada, and thus a new community was born – bestowed with the fittingly bellicose name Ajax, in honor of the HMS Ajax, a victorious British warship from the recently fought Battle of River Plate.
The end of the war saw the end of the DIL Pickering Works, but it was just the beginning for Ajax. The filling plant was transformed into an engineering campus for the University of Toronto and the town spread out as a modern planned community to accommodate the new students as well as the workers and their families who chose to stay on after the last shell rolled off the line at Pickering Works. In 1974 old Pickering Village was annexed by Ajax and today the town continues to grow as a thriving member of the Greater Toronto Area.