after the noble gentleman of ibbenbüren died out, ibbenbüren came under the exclusive rule of the counts of tecklenburg. this rule lasted until the end of the 15th or beginning of the 16th century, when ibbenbüren finally fell into possession charles' v. in 1548 by awkward and luckless tactics used by the counts of tecklenburg. karl donated it to his sister mary of habsburg, governor of the netherlands. ibbenbüren was assigned to the office lingen. into this period also the falls the beginning of coal mining.