Why was Shah Jahan under house arrest?

Answer 1

Soon after the completion of the Taj Mahal India in 1648, Shah Jahan became seriously ill. As he lay dying he witnessed the fierce hostility among his four sons in their struggle to succeed him. His four children had grown up in an atmosphere of bitter rivalry even though they were all the sons his beloved wife Mumtaz Mahal. The expectation of their father's death provoked them into a savage contest for power

Aurangzeb had an acute sense of political realism and a fierce appetite for power. He was the superior in both military talent and administrative skills and easily outclassed his brothers in the bid for power. After a bitter struggle he was crowned emperor in 1659. His father had not died as everyone had expected but sick and ailing, Shah Jahan was imprisoned by his son, the new emperor in the Agra fort.

There he remained, confined for eight years, under house arrest, until his death. From the balcony of Muasamman Burj tower he could look down on the beautiful monument he had created for his beloved wife, the Taj Mahal India.