Duke of Głogów in the context of "Silesian Piasts"

Sigismund I the Old (Polish: Zygmunt I Stary, Lithuanian: Žygimantas I Senasis; 1 January 1467 – 1 April 1548) was King of Poland and Grand Duke of Lithuania from 1506 until his death in 1548. Sigismund I was a member of the Jagiellonian dynasty, the son of Casimir IV and younger brother of Kings John I Albert and Alexander I Jagiellon. He was nicknamed "the Old" in later historiography to distinguish him from his son and successor, Sigismund II Augustus. Before ascending to the Polish and Lithuanian thrones, he was Duke of Głogów from 1499, Duke of Opava from 1501, and governor of Silesia from 1504 on behalf of his brother, King Vladislaus II of Bohemia and Hungary.

Sigismund was born in the town of Kozienice in 1467 as the fifth son of Casimir IV and his wife Elizabeth of Austria. He was one of thirteen children and was not expected to assume the throne after his father. Sigismund's eldest brother and rightful heir Vladislaus II instead became the King of Bohemia, Hungary and Croatia as the successor to George of Poděbrady in Bohemia and then to Matthias Corvinus in Hungary, thus temporarily uniting these kingdoms. When Casimir died, the Polish-Lithuanian realm was divided between the remaining two older sons, with John Albert being crowned King of Poland, and Alexander as Grand Duke of Lithuania. Alexander inherited Poland following John Albert's sudden death in 1501. Hence, Sigismund's reign only began when he succeeded Alexander to both titles in 1506 at the age of 39.

John I Albert (Polish: Jan I Olbracht; 27 December 1459 – 17 June 1501) was King of Poland from 1492 to his death and Duke of Głogów from 1491 to 1498. He was the fourth Polish sovereign from the Jagiellonian dynasty and the son of Casimir IV and Elizabeth of Austria.

Related to the House of Habsburg, John Albert was groomed to become emperor in the Holy Roman Empire, a plan that ultimately failed. He was well-educated and tutored by scholars such as Johannes Longinus and Callimachus, whom he had subsequently befriended. Heavily influenced by the Italian Renaissance, John sought to strengthen royal authority at the expense of the Catholic Church and the clergy. In 1487, he led a force against the Ottoman Empire and defeated the Tatars of the Crimean Khanate during the early phase of the Polish–Ottoman War. In the aftermath of the Bohemian–Hungarian War, John Albert attempted to usurp Hungary from his elder brother Vladislaus, but on 20 February 1491, he renounced his claim to Hungary in exchange for the Duchy of Głogów and the suzerainty over half of Silesia.