Ajmer was founded by a Rajput chieftain Raja Ajaypal Chauhan who also built first hill fort in India, the Tara Garh. As the fort was supposed to be invincible, it was named Ajay Meru (the Invincible Hill). Ajmer played a vital role in paving the way for British East India Company in India. The small town of Ajmer played an amazingly important role in India's history. It is located at the point where the Thar Desert begins and the rocky Aravalli Hills end, this was initially the stronghold of the powerful Chauhan Dynasty of Rajputs. Ajmer was brought under the control of Delhi Sultanate in 1193 when Ajaipal Chauhan was defeated by Mohammed Ghori. It was later returned to the local chieftains as a small tribute. In 1616 Jahangir met ambassador of King James, Sir Thomas Roe. In the 17th century Shah Jahan constructed marble pavilions around the Ana Sagar Lake. The Taragarh Fort was damaged badly during the Mughal war of succession between Aurangzeb and Dara Shikoh. The Scindia rulers of Gwalior took over Ajmer in the mid 18th century and the city was later handed over to the British in 1818.