The name was extremely popular among Polish royalty, with several leaders shaping the nation's history:
: Widely considered one of Poland's greatest kings. He is famously said to have "found Poland made of wood and left it made of stone" because of his extensive castle-building and modernization projects. He also founded the Jagiellonian University , one of the oldest in the world. kasimir
: Known for reuniting Poland after a period of internal collapse and pagan uprisings, earning him the title "the Restorer". The name was extremely popular among Polish royalty,
: A prince of the Jagiellon dynasty who was known for his exceptional piety, charity, and refusal of royal luxuries. He is the patron saint of Poland and Lithuania. Fictional: Kasimir Velikov : Known for reuniting Poland after a period
The most prominent "Kasimir" in modern history was a Russian avant-garde painter and art theorist. He is celebrated as the founder of , an art movement focused on basic geometric forms, such as circles, squares, and lines, painted in a limited range of colors.
: His most iconic work is the Black Square (1915), which he considered the "zero point of painting". Other famous works include White on White .