The story
Blend of Peter + Waterloo, in an ironic comparison to the Battle of Waterloo, which had taken place four years earlier.
Etymology from Wiktionary, CC BY-SA 4.0.
Peterloo
Today it means: The events of 16 August 1819, when cavalry charged into a large crowd that had gathered in St Peter's Field, Manchester, England, to demand the reform of parliamentary representation, killing fifteen and injuring hundreds more. Full definition →