1980 AD., Poland, socialist People's Republic, King Bolesław I commemorative, Warsaw mint, 50 Złotych, KM Y 114.

Poland, socialist People's Republic, King Bolesław I Chrobry commemorative, engraver: Stanislawa Watrobska-Frindl, Warsaw mint, 1980 AD.,
50 Złotych (ø 30,5 mm / 11,78 g), copper-nickel, 11,70 g. (?) theor. mint weight, mintage 2.564.000 , axis medal alignment ↑↑ (0°), reeded edge,
Obv.: POLSKA RZECZPOSPOLITA LUDOWA / 19 – 80 / {mW} / ZŁ 50 ZŁ , eagle dividing date, value below..
Rev.: BOLESŁAW I CHROBRY - 992 - 1025 , crowned bust of King Bolesław I Chrobry facing slightly right.
KM Y 114 ; Parchimowicz 258 ; Schön 110 .

Year / Mint Mark / Mintage
1980 / MW / 2.564.000
1980 / MW / 5,000 proof

Bolesław I the Brave (Polish: Bolesław I Chrobry, Czech: Boleslav Chrabrý; 967 – 17 June 1025), less often known as Bolesław I the Great (Polish: Bolesław I Wielki), was Duke of Poland from 992 to 1025, and the first King of Poland in 1025. As Boleslav IV, he was also Duke of Bohemia between 1002 and 1003. He was the son of Mieszko I of Poland by his wife, Dobrawa of Bohemia. According to a scholarly theory, Bolesław ruled Lesser Poland already during the last years of his father's reign. Mieszko I, who died in 992, divided Poland among his sons, but Bolesław expelled his father's last wife, Oda of Haldensleben, and his half-brothers and reunited Poland between 992 and 995.
More on https://en.wikipedia.org/wiki/Bolesław_I_the_Brave