Background
He was the second son of Duke Kasimir I of Silesia-Auschwitz (ruled 1406–1434).
He was the second son of Duke Kasimir I of Silesia-Auschwitz (ruled 1406–1434).
Several years after his father"s death Premislav received the dukedom of Tost, which he ruled for forty-five years (1439–1484). He died aged fifty-nine. Duke Premislav was married (1463) to Machna (1442–1472), the eldest daughter of Duke Nikolaus I of Silesia-Oppeln.
The couple left no male heirs, just a surviving daughter Margaret of Tost (1467 – November 8, 1531) who took holy orders and was appointed abbess of the convent of Street Klara in Breslau (1508–1531).