Baptism of Poland Day Date in the current year: April 14, 2025

Poland is one of the most religious countries in Europe and one of the most Catholic countries in the world: according to the 2021 census, 72.43% of the country’s citizens identified as Christian and 71.30% as Roman Catholic. The Christianization of Poland began in 966 during the reign of Mieszko I. It is believed to have paved the way for the creation of the first unified Polish state, Civitas Schinesghe, also known as the Principality of Poland or the Duchy of Poland.

Mieszko I was the ruler of the Polans, a Slavic tribe that inhabited the region now known as Greater Poland (Wielkopolska). The dates of his birth and the beginning of his reign are unclear, but he probably succeeded his late father sometime in the late 950s or early 960s.

In 964 Mieszko made an alliance with Boleslaus I, Duke of Bohemia. To cement the agreement, he married Boleslaus’s daughter Doubravka (Dobrawa). Most historians agree that Doubravka, who was an ardent Christian, played a crucial role in persuading her husband to convert to Christianity. Mieszko and most of his court converted to Christianity on Holy Saturday, April 14, 966. The location of the baptism is disputed, with the present-day cities of Gniezno and Poznań being the most likely sites.

Of course, even with Mieszko’s baptism Poland did not become Christian overnight; the spread of Christianity throughout the country was a long and arduous process that took centuries to complete. However, it was successful in the sense that it marked the beginning of Polish statehood, for in less than three decades Poland was recognized by the Pope and the Holy Roman Empire as an established Christian state.

The first Bishop of Poland, Jordan, was appointed by Pope John XIII in 968, during Mieszko’s reign. However, the ecclesiastical structure of Poland was established by Mieszko’s son, Bolesław I the Brave. It was during his reign that Holy Roman Emperor Otto III allowed the establishment of the Archdiocese of Gniezno, independent of the Archdiocese of Magdeburg. Dioceses were also established in Kołobrzeg, Kraków, and Wrocław.

In the 1030s, the Kingdom of Poland was destabilized by a series of pagan uprisings against the spread of the new religion, with many priests killed and churches and monasteries destroyed. Nevertheless, the Christianization of Poland continued, and by the 13th century the country was predominantly Roman Catholic.

The anniversary of Mieszko’s baptism was declared a public holiday in Poland in 2019. The main goal of the Baptism of Poland Day is to highlight the importance of baptism in the emergence of the Polish nation and the establishment of the Polish state. Although Poland has experienced rapid secularization in recent years, especially among young people, Christianity is still an important part of Polish national identity.