Khizir Khan Khilji was eldest son of Allahuddin Khilji from his wife Mallika Jahan daughter of Jalaluddin Khilji. Dewal Rani Devi was the daughter of Kamala Devi the favourite wife of Allauddin Khilji and her first husband, Raja of Guajarat Raj Karan deva II. Allauddin Khiljji married Kamala Devi and she became his favourite and requested that her daughter from first marriage be brought to Delhi back from her first husband.
A few days later Khizir Khan and Dewal Rani fell in love with each other. The marriage was met with opposition by Allauddin Khilji and Mallika Jahan because by relation they were half siblings. But Khizir Khan defied Allauddin Khilji orders to stay away from Dewal Rani and they both continued meeting. Mallika Jahan, Khizir’s mother was not fine with the relation and tried many ways to separate them like sending them away to different city and by keeping Dewal Rani in house arrest. But nothing worked, Khizir love for her only increased with every step to separate them. Finally seeing Khizirs despair at staying away from Dewal Rani, Mallika Jahan and Allauddin Khilji had no option but to agree for marriage of both.
The marriage of Khizir Khan and Dewal Ran took place in 1316. Mallik Kafur the commander of Allauddin Khilji instigated him to imprison Mlalika Jahan’s sons Khizir Khan and Shadi Khan in fort of Gwalior. Mallik Kafur treated Khizir Khan and his brother like enemy of state and tortured them. Dewal Rani was only constant companion of Khizir Khan in his imprisonment.
Allahuddin Khilji was on death bed in 1316 and asked for Khizir Khan so he can be anointed as next emperor but Mallik Kaafur cleverly delayed the matter till Allauddin was dead. Indeed Allauddin Khilji was killed by Mallik Kafur only as per many historians.
Mallik Kafur placed youngest son of Allauddin Khilji, a six year old called Umar on throne. He sent people to blind both Khizir and Shadi Khan. Mubarak Shah the third son of Allauddin Khilji and Mallika Jahan somehow escaped an assaination plot. A few months later bodyguards of Allauddin Khilji murdered Mallik Kafur and appointed Mubarak Shah as regent of Umar Shah. Mubarak Shah imprisoned Umar, the six year old kid and became emperor himself.
Mubarak too had an eye for Dewal Rani who was beautiful and asked Khizir to hand her over to him, but Khizir refused. Mubarak decided to kill Khizir and sent people to kill him in prison. In the attack, Dewal Rani’s both hands were cut off as she cling to Khizir as assains attacked him and refused to move back. Thus ended a great love story of forbidden love between Khizir Khilji and Dewal Rani. Mubarak forcibly took Dewal Rani in his harem and treated her as a slave girl to humiliate his brother Khizirs memories.
Please read more on Ishquia or Ashiqa / Mathnavi Duval Rani-Khizr Khan (Romance of Duval Rani and Khizr Khan) by Amir Khusrau