Hamir Dev belonged to the Chauhan dynasty and drew his lineage from Prithviraj Chauhan who enjoys a respectable place in the Indian history. During his 12 years' reign, Hamir Dev fought 17 battles and won 13 of them. He annexed Malwa, Abu and Mandalgarh and thus extended his kingdom to the chagrin of Delhi Sultan, Jalaluddin, who had misgivings about Hamir's intentions. Jalaluddin attacked Ranathambhor and had it under siege for several years. However, he had to return to Delhi unsuccessful.
Jalaluddin was assassinated by his nephew Allaluddin Khilji who then crowned himself as the new Sultan of Delhi. Muhammad Shah was instrumental in making this coup successful which earned him a basketful of privileges. Muhammad Shah was even allowed access to the harem as a result of which he soon built up a good rapport with its inmates.
Chimna was one of Allaudin's begums, but Allaudin never gave her as much attention as other begums of the harem received from him. He had inadvertently managed to antagonize her. To make things worse Chimna Begum saw a valiant soldier in Muhammad Shah and was extremely impressed by his courage and boldness. Soon the vindictive begum and the ambitious Muhammad Shah started a conspiracy to slay Allaudin. Their objective was to see Muhammad Shah as Sultan and the begum as queen. The conspiratorial plans somehow leaked out. Allaudin was enraged as he came to know of Muhammad Shah's intentions. To escape the fury of Allaudin, Muhammad Shah had to flee from Delhi along with his brother. He sought asylum in many nearby kingdom but no one was ready to stand up to the wrath of Allaudin.
Muhammad Shah approached Hamir Dev. The brave Rajput was moved by his humble pleading and misery and agreed to him shelter. Allaudin's ire was roused when he came to know of it. He immediately attacked the fort of Ranathambhor. The armies of Allaudin and Hamir Dev met in a battle on the banks of river Banas. The Rajputs had the initial victory. However, because of the personal feud between the Prime Minister and the Senapati (General-in-charge of the army) Hamir Dev's army got disorganized. The Prime Minister succeeded in getting the Senapati killed. Meanwhile, Allaudin reorganized his forces and made a renewed attack on the fort. Some unscrupulous officers of Hamir Dev, with Bhoj Dev as their leader, colluded with Allaudin and started giving him secret information about the fort. The war continued. The strong walls of the fort were strategically so situated that it was not possible to blow them down with gunpower, for the debris so created had already killed numerous soldiers of the Sultan in their futile attempt to break in to the fort. At last Allaudin sent a message to Hamir Dev saying that in case he was ready to hand over Muhammad Shah to him, he would go back to Delhi. Hamir Dev was too self respecting to make such an ignominious compromise. He sent back the messenger with the reply that when the Rajputs promised to protect someone, they even gave their lives for his safety. Muhammad Shah saw the hopelessness of the situation and conselled Hamir Dev to hand him over to Allaudin rather than fight such a long drawn-out war and suffer such an enormous loss of lives and resources. Allaudin's army was immense. He put a complete siege on the Ranathambhor fort. Bhoj Dev and his informers kept on supplying him information on the food of water situation inside the fort. The ill-fated war bended with the Sultan's legions emerging victorious. The female members of the Rajput kingdom committed jauhar and gave up lives on the pyres. Hamir Dev, himself, severed his head and put it in front of Lord Shiva's idol as an offering.