It was (re)created on January 1, 1999, as a result of the Polish local government reforms passed in 1998. Its administrative seat and largest town is Mińsk Mazowiecki, which lies 39 kilometres (24 mi) east of Warsaw. The county contains three other towns: Sulejówek, 21 km (13 mi) west of Mińsk Mazowiecki, Halinów, 16 km (10 mi) west of Mińsk Mazowiecki, and Kałuszyn, 17 km (11 mi) east of Mińsk Mazowiecki.