There are two great heroes of Babylonian fame who link with Perseus and Hercules, Sigurd and Siegfried, Dietrich and Finn-mac-Coul. These are Etana and Gilgamesh, two legendary kings who resemble Tammuz the Patriarch referred to by Berosus, a form of Tammuz the Sleeper of the Sumerian psalms. One journeys to the Nether World to obtain the Plant of Birth and the other to obtain the Plant of Life. The floating legends with which they were associated were utilized and developed by the priests, when engaged in the process of systematizing and symbolizing religious beliefs, with purpose to unfold the secrets of creation and the Otherworld. Etana secures the assistance or a giant eagle who is an enemy of serpents like the Indian Garuda, half giant, half eagle. As Vishnu, the Indian god, rides on the back of Garuda, so does Etana ride on the back of the Babylonian Eagle. In one fragmentary legend which was preserved in the tablet-library of Ashur-banipal, the Assyrian monarch, Etana obtained the assistance of the Eagle to go in quest of the Plant of Birth. His wife was about to become a mother, and was accordingly in need of magical aid. A similar belief caused birth girdles of straw or serpent skins, and eagle stones found in eagles' nests, to be used in ancient Britain and elsewhere throughout Europe apparently from the earliest times.[191] On this or another occasion Etana desired to ascend to highest heaven. He asked the Eagle to assist him, and the bird assented, saying: "Be glad, my friend. Let me bear thee to the highest heaven. Lay thy breast on mine and thine arms on my wings, and let my body be as thy body." Etana did as the great bird requested him, and together they ascended towards the firmament. After a flight which extended over two hours, the Eagle asked Etana to gaze downwards. He did so, and beheld the ocean surrounding the earth, and the earth seemed like a mountainous island. The Eagle resumed its flight, and when another two hours had elapsed, it again asked Etana to look downwards. Then the hero saw that the sea resembled a girdle which clasped the land. Two hours later Etana found that he had been raised to a height from which the sea appeared to be no larger than a pond. By this time he had reached the heaven of Anu, Bel, and Ea, and found there rest and shelter. Here the text becomes fragmentary. Further on it is gathered from the narrative that Etana is being carried still higher by the Eagle towards the heaven of Ishtar, "Queen of Heaven", the supreme mother goddess. Three times, at intervals of two hours, the Eagle asks Etana to look downwards towards the shrinking earth. Then some disaster happens, for further onwards the broken tablet narrates that the Eagle is falling. Down and down eagle and man fall together until they strike the earth, and the Eagle's body is shattered.