After Ratan Singh's death his successor Laxman Singh tried to capture Chittor and fought a battle with Tughlaq near Chittor. He died along with his son Ari. His second son Ajay was severely wounded but was taken away from the battlefield by other soldiers and survived. Ajay was not a powerful ruler and his sons were likewise. Ajay knew that Ari had a son Hammir and he called Hammir to come to him.
Hammir, along with his mother came to see his uncle. Ajay said that he had grown weak and a dacoit, Munja Balicha, was wreaking havoc in Rawal Ajay's domain. Hammir vowed that he would take care of Munja.
Hammir took seven warriors with him and set out to finish Munja. Hammir at this stage was just a teenager. Munja was tracked. When Munja was riding with his band to plunder a village, Hammir stood in his way on his white steed. Munja asked him to leave the way or die. Hammir challenged him to a duel and seeing that Hammir was just a teenager Munja readily agreed. Hammir killed Munja and brought his head and put it at Rawal Ajay's feet and told his uncle that Munja will never be a problem again. Rawal Ajay realized Hammir should be the ruler and he coronated Hammir as the new ruler of Mewar. Ajay's sons were unhappy with this and decided to move to Maharashtra. Do note that Chittor was called Khijarabad at this time as Ala ud din had renamed it after his son and at Hammir's coronation was ruled by Muhammad bin Tughlaq.
Hammir captured Chittor. Tughlaq became very unhappy and launched a massive campaign against Hammir which he led himself. Hammir knew as soon as he captured Chittor that Tughlaq would attack him. He rallied all nearby rajput states to join him and they did. Battle was fought and Tughlaq was badly defeated and captured. After Tughlaq paid a hefty fees and surrendered all of Mewar's territory he was let go. After this defeat Mewar was never attacked by Tughlaq.