Louis I the Fair, also known as the Wise or the Righteous or Louis I of Brzeg was Duke of Legnica from 1342 to 1346 and of Brzeg from 1358 until his death. A member of the Silesian Piasts, he was also regent of Legnica from 1364 to 1373.

The Duke of Silesia was the title of sons and descendants of the Polish Duke Bolesław III Wrymouth. In accordance with the last will and testament of Bolesław, upon his death his lands were divided into four or five hereditary provinces distributed among his sons, and a royal province of Kraków reserved for the eldest, who was to be High Duke of all Poland. This was known as the fragmentation of Poland. Subsequent developments lead to further splintering of the duchies.