What river, above all, is the river of India?

The Ganges (also Ganga Devanāgarī: गंगा) is the major river in the Indian subcontinent flowing east through the eponymous plains of northern India into Bangladesh. The 2,510 km (1,557 mi) long river begins at the Gangotri Glacier in the Indian state of Uttarakhand in the central Himalayas and drains into the Bay of Bengal through its vast delta in the Sunderbans. It has enjoyed a position of reverence for millennia among India's Hindus, by whom it is worshipped in its personified form as the goddess Ganga.

Source: New World Encyclopedia