In Gloranthan Lore, the earth rose up from the sea, forming the continents and the land. During the Gods War, the Sea invaded the land, sending assaults inland to reconquer the terrestrial world.

These formed the first rivers and streams, so in Glorantha, rivers once ran uphill! They were the advance guard of the Sea’s Reconquista. They even invaded the golden sky, forever turning it blue.

The rivers didn’t switch directions and flow back to the ocean until the Chaos Rift opened, when the Sea tried to fill and close the rift by hurling itself into oblivion.