 Archbishop Frederick of Cologne also broke with Henry during a campaign against the Frisians, who refused to pay the annual tribute and Henry allegedly sacrificed a Cologne troop contingent to the Frisians.The citizens of Cologne complained about the draconian regiment of one of Henry's ministerials and Archbishop Friedrich denounced the catastrophic condition of the church in a letter.The episcopal seats of Worms and Mainz remained vacant for years and the secular rights of the bishops were carried out by royal administrators ("villici").