St Mary's Church (Mariakirken) was the royal chapel and had an important political role, as its provost from 1314 also was Chancellor of Norway. It was built originally in 1050 AD, but rebuilt and expanded several times. Final additions made in the 1300s. In the beginning of the 14th century, it was the third largest church in the country, and in the Middle Ages it was the royal chapel. The church was set on fire by Swedish forces in connection with an attack in 1523. After the Reformation, it was so dilapidated that it could not be repaired and was demolished in 1542.
Excavations were first conducted in 1867 under Nicolay Nicolaysen and later in the 1960s under the leadership of Håkon Christie. Remains of two people, deemed to be King Haakon V (1270-1319) and his Queen consort Euphemia of Rügen, were discovered during excavations of the ruins of the church and reinterred in the Royal Mausoleum in Akershus Castle.References:
Tyniec Benedictine abbey was founded by King Casimir the Restorer probably around 1044. Casimir decided to rebuild the newly established Kingdom of Poland, after a Pagan rebellion and a disastrous Czech raid of Duke Bretislaus I (1039). The Benedictines, invited to Tyniec by the King, were tasked with restoring order as well as cementing the position of the State and the Church. First Tyniec Abbot was Aaron, who became the Bishop of Kraków. Since there is no conclusive evidence to support the foundation date as 1040, some historians claim that the abbey was founded by Casimir the Restorer’ son, King Boleslaw II the Generous.
In the second half of the 11th century, a complex of Romanesque buildings was completed, consisting of a basilica and the abbey. In the 14th century, it was destroyed in Tatar and Czech raids, and in the 15th century it was rebuilt in Gothic style. Further remodelings took place in the 17th and 18th centuries, first in Baroque, then in Rococo style. The abbey was partly destroyed in the Swedish invasion of Poland, and soon afterwards was rebuilt, with a new library. Further destruction took place during the Bar Confederation, when Polish rebels turned the abbey into their fortress.
In 1816, Austrian authorities liquidated the abbey, and in 1821-1826, it was the seat of the Bishop of Tyniec, Grzegorz Tomasz Ziegler. The monks, however, did not return to the abbey until 1939, and in 1947, remodelling of the neglected complex was initiated. In 1968, the Church of St. Peter and Paul was once again named the seat of the abbot. The church itself consists of a Gothic presbytery and a Baroque main nave. Several altars were created by an 18th-century Italian sculptor Francesco Placidi. The church also has a late Baroque pulpit by Franciszek Jozef Mangoldt.