The area became Prussian in 1815. To help govern its new land Prussia made three districts Heinsberg, Erkelenz and Geilenkirchen in 1816. In 1932 the districts of Heinsberg and Geilenkirchen were joined, and in 1972 the Erkelenz district was joined to the others as well. In 1975 the municipality of Niederkrüchten was moved to the district Viersen. That was the last change to the district's size