Jan Calkoen (1694–1780) was appointed to the city council by Stadholder Willem IV of Orange in 1748. He was not, however, a fervent supporter of the House of Orange. In 1752 he joined the ‘Correspondentie’ group. This was composed of certain members of the ‘regent’ class who had made a secret pact to restrict the influence of the stadholder by playing the positions of power into each other’s hands.