Ganesh Chaturthi celebrates the birth of Ganesha, the elephant-headed son of Shiva and Parvati, remover of obstacles and lord of beginnings, worshipped before any undertaking. It falls on the fourth day (chaturthi) of the bright fortnight of Bhadrapada (August-September) and runs for up to ten days, ending on Anant Chaturdashi. Its central act is the installation of a clay image of Ganesha, in the home or in a large public pavilion, and its daily worship with flowers, sweets (above all the dumpling modak, said to be his favourite), incense and song, before the image is finally taken in procession and immersed in water (visarjan), returning the god to the elements.
The festival is especially identified with Maharashtra, where the nineteenth-century nationalist Bal Gangadhar Tilak transformed it, around the 1890s, from a domestic rite into a large public celebration, using the shared festival to bring people together and build a sense of common cause under colonial rule; the great street mandals of Mumbai and Pune descend from this. Its modern scale has also raised environmental concern over the plaster-of-Paris images and chemical paints once common, prompting a movement toward eco-friendly clay idols. Ganesh Chaturthi joins domestic devotion, public spectacle and a distinctly modern political history in a single festival.