Complex sentence: In 1425 Humphrey deserted his wife, who found herself obliged to submit to her cousin, Philip III, Duke of Burgundy, after being besieged in the city of Mons in Hainault, and she was placed under house arrest in the chateau of Ghent.
Split into simpler sentences: In 1425 Humphrey deserted his wife, who found herself obliged to submit to her cousin, Philip III, Duke of Burgundy, after being besieged in the city of Mons in Hainault. Jacqueline was placed under house arrest in the chateau of Ghent.