Rustam Khan was the Qazi of Lahore. The duty of the Qazi was to dispense justice. Guru Nanak had condemned the Qazis of his times. He blamed them as bribe seekers and doing no justice to the people. Rustam Khan was the Chief Qazi of Lahore. He was a fanatic Muslim. He discriminated between the Hindus and the Muslims. He and Musaud Sirhindi, a leader of Naqash Bandi sect of the Muslims, were against Guru Har Gobind. They found in him a hurdle for them. They could not convert the Hindus to their faith; because the Guru’s teachings, which were for the whole mankind, stood in their way. Both the Hindus as well as the Muslims were his devotees.
Kaulan was the daughter of Qazi Rustam Khan.
She was a pious girl. She did not like the fanaticism of her father. She fell under the influence of Sai Mian Mir. Mian Mir was a great Sufi Saint of Lahore. He had laid the foundation stone of the Harmandar Sahib at Amritsar. He had great regards for the Sikh Gurus. Kaulan was attracted towards the Sikh way of life. She disclosed her mind to Sai Mian Mir. He helped her and she reached the court of Guru Har Gobind.
The Qazi was furious, He could not tolerate to see her daughter adopting the Sikh faith. He, Masaud Sirhindi and other bigot Muslims, complained against the Guru. Jahangir was, then, weff diposed towards the Guru. He did not pay much attention. The Qazi failed to do anything to harm the Guru.
After the death of Jahangir, Shah Jahan occupied the throne. He was not liberal in religious matters. He did not allow the Hindu temples in Banaras to be completed. He punished those Hindus of the Punjab who had married Muslim girls. To escape the wrath of the Emperor, some 4000 Hindus had to change their religion.
The Qazi again brought the case of Kaulan before Shah Jahan. Shah Jahan sent a force of 7000 strong againtthe Guru. Two sons of the Qazi also went to fight against the Guru. However, they were all defeated by the Guru.
Kaulan remained in Amritsar as a pious lady.
Guru Har Gobind treated her very kindly. The Sikhs respected her. Guru Har Gobind built a tank and named it Kaulsar. Thus he immortalised her.
The Kaulsar tank reminds us of Kaulan even today.