The word Kathak has been derived from the word Katha which means a story. Kathakars or story-tellers, are people who narrate stories largely based on episodes from the epics, myths and legends. It probably started as an oral tradition. Mime and gestures were perhaps added later on to make the recitation more effective. Thus evolved a simple form of expressional dance, providing the origins of what later developed into Kathak as we see it today.
The Vaishnavite cult which swept North India in the 15th century, the resultant bhakti movement contributed to a whole new range of lyrics and musical forms. The Radha-Krishna theme proved immensely popular along with the works of Mirabai, Surdas, Nandadas and Krishnadas.