He was the only son of John I, Duke of Lubin, by his wife Hedwig, daughter of Ludwik II of Brzeg.

The successive deaths of his uncle Henry X (in 1452) and his own father (in 1453) left Frederick I as the last male representative of the Legnica-Brzeg branch of the Piast dynasty.

The seven-year-old prince succeeded John I in Chojnow and Strzelin under the regency of his mother, the Dowager Duchess Hedwig.

One year later (1454), Frederick I inherited Olava and Niemcza after the death of his paternal grandmother Margareta of Opole; shortly after, he also received Legnica from the Kingdom of Bohemia.

The regency of Dowager Duchess Hedwig ended in 1466, when Frederick I was formally proclaimed an adult and was able to rule by himself.