The Premonstratensian canons founded the monastery, dedicated to Saint Olav, in Tønsberg in the second half of the 12th century, possibly in or shortly before 1191. The church was completed by 1207, as is confirmed by the record of a burial there in that year. This was a very wealthy establishment with considerable influence in the affairs of its time. It was nevertheless unable to resist secularisation in 1532 during the Reformation, when King Fredrik I granted it as a fief to Erik Ugerup. The monastic buildings were badly damaged by a fire in 1536, although possibly some may have been repaired to serve as the residence of the owner. The extensive estates later passed into the hands of the earls of Jarlsberg.
The church was extremely unusual in that it was round, the only round church in the province and one of the largest in the whole of Scandinavia. There may be some connection between the shape and the cult of Saint Olav, which was centred on his shrine in the octagonal chapel at the east end of Nidaros Cathedral.
The nave had a diameter of about 23 metres. There was a round apse at the east end, with another round chamber - probably the sacristy - opening off it, and portals to the north, west and south.
Archaeological excavations were carried out in 1877, 1929, 1963–67 and 1969-71. Although it seems clear that the conventual buildings were attached in some way to the church, it has not so far been possible to establish their exact layout. The burial ground must have been to the north and east of the church.
The ruins of the round church are still to be seen at Storgaten 17 and 19, with some remains of conventual buildings to the south-east. Some have been incorporated into the structure of the Tønsberg Municipal Library.References:
The Palazzo Colonna is a palatial block of buildings built in part over ruins of an old Roman Serapeum, and has belonged to the prestigious Colonna family for over twenty generations.
The first part of the palace dates from the 13th century, and tradition holds that the building hosted Dante in his visit to Rome. The first documentary mention notes that the property hosted Cardinal Giovanni and Giacomo Colonna in the 13th century. It was also home to Cardinal Oddone Colonna before he ascended to the papacy as Martin V (1417–1431).
With his passing, the palace was sacked during feuds, and the main property passed into the hands of the Della Rovere family. It returned to the Colonna family when Marcantonio I Colonna married Lucrezia Gara Franciotti Della Rovere, the niece of pope Julius II. The Colonna"s alliance to the Habsburg power, likely protected the palace from looting during the Sack of Rome (1527).
Starting with Filippo Colonna (1578–1639) many changes have refurbished and create a unitary complex around a central garden. Architects including Girolamo Rainaldi and Paolo Marucelli labored on specific projects. Only in the 17th and 18th centuries were the main facades completed. Much of this design was completed by Antonio del Grande (including the grand gallery), and Girolamo Fontana (decoration of gallery). In the 18th century, the long low facade designed by Nicola Michetti with later additions by Paolo Posi with taller corner blocks (facing Piazza Apostoli) was constructed recalls earlier structures resembling a fortification.
The main gallery (completed 1703) and the masterful Colonna art collection was acquired after 1650 by both the cardinal Girolamo I Colonna and his nephew the Connestabile Lorenzo Onofrio Colonna and includes works by Lorenzo Monaco, Domenico Ghirlandaio, Palma the Elder, Salviati, Bronzino, Tintoretto, Pietro da Cortona, Annibale Carracci (painting of The Beaneater), Guercino, Francesco Albani, Muziano and Guido Reni. Ceiling frescoes by Filippo Gherardi, Giovanni Coli, Sebastiano Ricci, and Giuseppe Bartolomeo Chiari celebrate the role of Marcantonio II Colonna in the battle of Lepanto (1571). The gallery is open to the public on Saturday mornings.
The older wing of the complex known as the Princess Isabelle"s apartments, but once housing Martin V"s library and palace, contains frescoes by Pinturicchio, Antonio Tempesta, Crescenzio Onofri, Giacinto Gimignani, and Carlo Cesi. It contains a collection of landscapes and genre scenes by painters like Gaspard Dughet, Caspar Van Wittel (Vanvitelli), and Jan Brueghel the Elder.
Along with the possessions of the Doria-Pamphilij and Pallavacini-Rospigliosi families, this is one of the largest private art collections in Rome.