H. McLeod, basing his work on the martial race theory, says that the Jats began to join Sikhism in large numbers during the period of the sixth guru, Hargobind, but this theory has been rebutted by Jagjit Singh, a Sikh historian.At least seven of the 12 Sikh "Misls" (Sikh confederacies) were led by Jat Sikhs.