Complex sentence: He had no intention of allowing Martel to catch him unaware and dictate the time and place of battle, as his father had, and concentrated instead on seizing a substantial portion of the coastal plains around Narbonne in 736 and heavily reinforced Arles as he advanced inland.
Split into simpler sentences: He had no intention of allowing Martel to catch him unaware and dictate the time and place of battle, as his father had. He concentrated instead on seizing a substantial portion of the coastal plains around Narbonne in 736 and heavily reinforced Arles as he advanced inland.