Query: In what year did the establishment of the Qutb dynasty occur?
Context: Sultan Quli, a governor of Golkonda, revolted against the Bahmani Sultanate and established the Qutb Shahi dynasty in 1518; he rebuilt the mud-fort of Golconda and named the city "Muhammad nagar". The fifth sultan, Muhammad Quli Qutb Shah, established Hyderabad on the banks of the Musi River in 1591, to avoid the water shortages experienced at Golkonda.