Widewuto (also Viduutus, Vidvutus, Witowudi, Waidewut) was a legendary king of the pagan Prussians who ruled along with his elder brother, the high priest Bruteno in the 6th century AD. They are known from writings of 16th-century chroniclers Erasmus Stella, Simon Grunau, and Lucas David. Though the legend lacks historical credibility, it became popular with medieval historians. It is unclear whether the legend was authentically Prussian (i.e. recorded from Prussian mythology) or was created by Grunau (possibly inspired by Biblical Moses and Aaron), though Lithuanian researchers tend to support in its authenticity.
According to the legend, Widewuto and Bruteno were kings of the Cimbri. Driven out by the Goths from their homeland, the Cimbri arrived to Ulmiganea, inhabited by rather primitive people who had no agriculture or cities. Widewuto and Bruteno civilized the region and named it Prussia after Bruteno (Pruteno). Gintaras Beresnevičius noted that such arrival has a lot in common with the origin legend of the Lombards. Widewuto ruled wisely and issued laws regulating family life (for example, men could have three wives; burning of gravely sick relatives was allowed; infidelity was punished by death), public life (for example, slavery was prohibited; distinguished warriors with a horse were raised to nobility), and punishments for criminal activity. Bruteno was the high priest (criwo cyrwaito) in charge of religious life. Widewuto had twelve sons, whose names were memorialized in the districts of Prussia. For example, Lithuania was named after eldest son Litvas, Sudovia after Sudo, etc. At the age of 116, Widewuto burned himself together with Bruteno in a religious ceremony in the temple of Romuva. After their deaths the brothers were worshiped as god Wurskaito.
Widewuto had a white flag, measuring five by three ells. The flag had portraits of three Prussian gods, which Grunau reproduced in his work. On the left was the god of the underworld, Peckols – an old man with white beard and white scarf on his head. Middle-aged thunder god, Perkūnas, with fiery hair was in the middle. The god of crops, Patrimpas, was portrayed as a young beardless man wearing a wreath of grain ears. The flag also displayed mysterious symbols, somewhat similar to Cyrillic. Several linguists unsuccessfully attempted to decipher the writing hoping to discover the ancient Prussian writing system.