Tyrensaga

This tome is a collection of the most important histories, oral traditions, and religious pronouncements in the Tyrian religion. On its cover is a silver embossed depiction of the three-faced god holding the Hammer. 
...and so, the three heroes, Valkain, Frighand and Enya met with the ice sorcerer Mulcairn during the conjunction of the Treblodsluna and called forth Tyr in a mighty sacrifice of ten-thousand souls using the (illegible) and banished Sangvar and her forces in the Blodenskrieg...
...Having seen the realm of humanity stagnate since the Blodenskrieg and laid waste by invaders, Tyr directly intervened and walked Erden in the guise of a man, Holm. Holm defeated the orcs and forged the Empire from the disparate Nordling tribes. Holm bedded the Sun itself and from the light of the Sun he had three daughters. Holm named his three daughters after the heroes of old: Valka, Enya, and Friga, and they became the Valkyr...
...Holm departed back to the Overhall upon the Haloghast. His daughters returned with him and sometimes walk the Ethereal to add souls to Tyr's heavenly host, the Einherjar...
...It is said that from time to time Valka and Tyr quarrel, for Valka cares much for the fate of humanity, and that she has stolen his Hammer and thrown it down to Erden to aid mortals...