Complex sentence: The cathedral is the supposed place of the baptism of Mieszko I. Built in the second half of the 10th century, it was raised to the status of a cathedral in 968 when the first missionary, Bishop Jordan, came to Poland.
Split into simpler sentences: The cathedral is the supposed place of baptism of Mieszko I. Build in the second half of the 10th century. It was raised to the status of a cathedral in 968 when the first missionary Bishop Jordan came to Poland.