600th anniversary of the Jagiellonian university in Kraków. The Jagiellonian university was founded in 1364. The people depicted on these stamps have all studied there.
(Casimir III the Great)
Uniwersytet Jagiełłoński = The Jagiellonian University.
Find other Polish stamps depicting Mikołaj Kopernik
Kazimierz III Wielki (Casimir III the Great)
Mikołaj Kopernik (Nicolaus Copernicus)
Władysław II Jagiełło (Wladislaus Jagiello)