Complex sentence: The historic county of Monmouthshire was formed from the Welsh Marches by the Laws in Wales Act 1535, bordering Gloucestershire to the east, Herefordshire to the northeast, Brecknockshire to the north, and Glamorgan to the west.
Split into simpler sentences: The historic county of Monmouthshire was formed from the Welsh Marches by the Laws in Wales Act 1535. It bordered Gloucestershire to the east, Herefordshire to the northeast, Brecknockshire to the north, and Glamorgan to the west.