Era beginning/end
The Aesir Gods were jealous of Ymir's power, and so they attacked the giant together while he slept. Ymir's wounds spilled out so much blood that it filled the Primordial Void and drowned many of the Jotnar. The remaining Giants fled and hid in the misty lands of Niflheim, founding a new kingdom known as Jotunheim. The Aesir Gods were left unopposed to rule over the rest of existence, building several new realms from the flesh and bones of Ymir.
The primordial Giant Ymir was the first life to spring into existence in the universe, and it is from Ymir that all other life originated. Ymir created the first Giants and the first Gods, but was betrayed and slain by his offspring. From his body, the Gods formed the realms of creation, and filled these lands with new life.