Complex sentence: In 1813, his son, King William I returned to the Netherlands and became the first Dutch monarch from the House of Orange; the first king was Louis Bonaparte (1778-1846).
Split into simpler sentences: In 1813, his son, King William I returned to the Netherlands and became the first Dutch monarch from the House of Orange. The first king of Holland (1806-1810) was Louis Bonaparte (1778-1846).