Once the world was overburdened by the unnecessary defense force of different kings, who were actually demons but were posing themselves as the royal order. At that time, the whole world became perturbed, and the predominating deity of this earth, known as Bhumi, went to see Lord Brahma to tell of her calamities due to the demoniac kings. Bhumi assumed the shape of a cow and presented herself before Lord Brahma with tears in her eyes. She was bereaved and was weeping just to invoke the lord’s compassion. She related the calamitous position of the earth, and after hearing this, Lord Brahma became much aggrieved, and he at once started for the ocean of milk, where Lord Visnu resides. Lord Brahma was accompanied by all the demigods headed by Lord Siva, and Bhumi also followed. Arriving on the shore of the milk ocean, Lord Brahma began to pacify Lord Visnu, who formerly saved the earthly planet by assuming the transcendental form of a boar.
Krsna Book 1: The Advent of Lord Krsna