Nawab Kaim Khan embraced Islam in 754 Hijra. In 760 Hijra, Sultan Feroz Shah appointed him the Governor of Hisar-e-Firoza with the title of Khan-e-Jehan.The above indicates a coversion to Islam in about AD 1352. Nawab Kaim Khan continued as the Governor of Hisar in the times of Muhammad bin Tughluq and Khizr Khan. Khizr Khan defeated Daulat Khan Lodhi, who was at the helm of the Delhi Sultanate for a year and three months, and imprisoned him under Kaim Khan at Hisar-e-Firoza. Later Khizr Khan developed differences with Kaim Khan. Khizr Khan was on a military campaign when he received the information that Ameers Kaim Khan, Ikhtiar Khan, and former members belonging to the court of Sultan Mahmud Shah Tughlaq were planning to dethrone him. Khizr Khan left the campaign and while returning to Delhi, invited Nawab Kaim Khan and the others to a meeting held on the banks of Jumna where they were murdered on 20th Jamadi-ul-Awal, 822 Hijra. Tareekh-e-Farishta and Tarik-e-Tabqat-e-Akbari also corroborate this incident. It is believed[by whom?] that Kaim's body was then thrown in the river Jumna as his burial place is not mentioned in history. Khizr Khan went on to establish the Sayyid dynasty.
Nawab Kaim Khan had six sons, named Muhammad Khan, Taj Khan, Quttab Khan, Mohan Khan, Ikhtiar Khan, and Wahid Khan. During the life of the Nawab, Muhammad Khan lived in Hisar while Taj Khan and Quttub Khan ruled Tussam in Punjab. Mohan Khan and Ikhtiar Khan were the rulers of Fatehabad[disambiguation needed] and Dhosi.
After the death of their father at the hands of Khizr Khan, they dispersed and chose to avoid confrontation with Hakim-e-Delhi (ruling power in Delhi). Taj Khan later became the Nawab of Hisar, ruling from 1420 - 1446 AD. After death of Taj Khan his eldest son Fateh Khan was made Nawab of Hisar but Bahlol Lodi expelled Fatehkhan from Hisar. Taj Khan's brother, Muhammad Khan was made Nawab of Hansi but he was also expelled. Fateh Khan and Muhammad Khan came to Shekhawati area of Rajasthan and established the states of Fatehpur and Jhunjhunu respectively. Elder brothers Nawab Zainudin Khan and his son Nawab Pahryan Khan and Nawab Jabeerudin Khan founded the states of Narhar, Barwasi, Jharo Dapti, and Kayad.
In the Mughal era, Nawab Alaf Khan - Nawab Of Fatehpur became the commander of Rajput forces in the army of Emperor Jahangir. According to Tuzk-e-Jahangiri, he conquered Qilla Of Kongrah and assisted in the battle of Deccan. He is considered as the most prominent personality after Qaim Khan. Later in mid 20th Century Late Nawab Prince Mohammed Bakhtawar Khan became a very significant figure in India, and in his legacy apart from being a major Prominent Business, Landlord Hyderabad (India) & philanthropist, whose son Prince Mumtaz Ali Khan became First Muslim Kaimkhani MNA Hyderabad, Deccan, India, along with son Prince Mohammed Ishaq Ali Khan who was First Kaim Khani to settle in UK.