Punjabi poetry has always been overtly political in style and content. Guru Nanak, the first Sikh Guru, challenged Mughal emperor Babur in his Baburbani as leading a paap ki janj—army of sin. Sufi poets like Bulle Shah openly criticised the dominant orthodoxies of the time. Popular qissas—stories in verse—celebrated the defiance of lovers like Sohni-Mahiwal and Heer-Ranjha.Vaars, heroic ballads eulogising warriors, social bandits, religious heroes and freedom fighters, celebrated their defiance, resistance and sacrifice against political tyranny. The folk poetry sung by the bards, dhādi and kavishars, along with the Sikh ardas, forms the collective consciousness of Punjabis. In the 20th century, this tradition was carried forward by poets like Avtar Singh Sandhu aka Paash, Sant Ram Udasi, Lal Singh Dil and Harinder Singh Mehboob.