These days the accursed infidel of Gobindwal was very fortunately killed. It is a cause of great defeat for the reprobate Hindus. With whatever inten… - Guru Arjan

Arjun’s martyrdom inspired his own son, Hargobind, to arm his comrades, who stood ready to defend their religion with their lives, converting the pacifist faith of Guru Nanak into a militant new order pitted against Mughal tyranny.

There was a Hindu named Arjan in Gobindwal on the banks of the Beas River. Pretending to be a spiritual guide, he had won over as devotees many simple-minded Indians and even some ignorant, stupid Muslims by broadcasting his claims to be a saint. They called him guru. Many fools from all around had recourse to him and believed in him implicitly. For three or four generations they had been peddling this same stuff. For a long time I had been thinking that either this false trade should be eliminated or that he should be brought into the embrace of Islam. At length, when Khusraw passed by there, this inconsequential little fellow wished to pay homage to Khusraw. When Khusraw stopped at his residence, [Arjan] came out and had an interview with [Khusraw]. Giving him some elementary spiritual precepts picked up here and there, he made a mark with saffron on his forehead, which is called qashqa in the idiom of the Hindus and which they consider lucky. When this was reported to me, I realized how perfectly false he was and ordered him brought to me. I awarded his houses and dwellings and those of his children to Murtaza Khan, and I ordered his possessions and goods confiscated and him executed.

The Mughal rulers of the Punjab were evidently concerned with the growth of the Panth, and in 1605 the Emperor Jahangir made an entry in his memoirs, the Tuzuk-i-Jahāṅgīrī, concerning Guru Arjan's support for his rebellious son Khusrau Mirza. Too many people, he wrote, were being persuaded by his teachings, and if the Guru would not become a Muslim the Panth had to be extinguished. Jahangir believed that Guru Arjan was a Hindu who pretended to be a saint, and that he had been thinking of forcing Guru Arjan to convert to Islam or his false trade should be eliminated, for a long time. Mughal authorities seem plainly to have been responsible for Arjan's death in custody in Lahore, and this may be accepted as an established fact. Whether death was by execution, the result of torture, or drowning in the Ravi River remains unresolved. For Sikhs, Arjan is the first martyr Guru.