Complex sentence: The site of "Shahjahanabad" is north of earlier settlements of Delhi, its southern part overlaps some of the area settled during the Tughlaqs in 14th century, when it was the seat of Delhi Sultanate.
Split into simpler sentences: The site of "Shahjahanabad" is north of earlier settlements of Delhi. Its southern part overlaps some of the area that was settled during the Tughlaqs in 14th century when it was the seat of Delhi Sultanate.