The original parish church from the early 15th century was established by Prince Janus I.the Elder. The church was changed into the cathedral in 1798. Over the centuries, the Cathedral of St. John the Baptist was developed and new components were added, e.g. the chapel. The Cathedral of St. John the Baptist was connected with the nearby Royal Castle through a passage in the Gothic style.
The cathedral is connected with various important historical events. The last coronation was held in the cathedral in 1764 when Stanislav II August Poniatowski became the king. Cathedral of St. John the Baptist was seriously damaged - or rather nearly destroyed during the Second World War. Between 1947 - 1956 , Cathedral of St. John the Baptist was rebuilt into as a three-aisled church . The main facade was restored in the Mazovia Gothic style, following the design by John Zachwatowicz.
The Cathedral of St. John the Baptist is a national cemetery as outstanding personalities were buried in the crypt. During your tour around Cathedral of St. John the Baptist, you will see tombs and sarcophagi of Mazovian princes and archbishops of Warsaw and, for example, Henryk Sienkiewicz and a Cardinal Štěpán Wyszyński were buried there as well.
Just next to the cathedral you will come across a bell tower with a gate. The original tower was built in the 1st half of the 17th century. The present appearance is the result of the reconstruction between 1949 and 1953.