Complex sentence: Shrewsbury was until 2009 an unparished area and had no town or parish council (s), instead the Mayor of Shrewsbury and Atcham was also the mayor of the town.
Split into simpler sentences: Shrewsbury was until 2009 an unparished area and had no town or parish council (s). Instead, the Mayor of Shrewsbury and Atcham was also the mayor of the town.