Before the St. Catherine's was built, a 14th-century Dominican church occupied the area. When the Jesuits arrived in Zagreb in the early 17th century, they thought the original church too rundown and inadequate, and worked to build a new church. Construction began in 1620 and was completed in 1632. A monastery was built adjacent to the church, but now the spot is home to the Klovićevi dvori art gallery.
St. Catherine's church was victim to fire twice in history: once in 1645 and again in 1674, devastating the interior. The church was refurnished with help from wealthy Croatian nobles, and in return, they were allowed to display their family coat-of-arms or have the honour to be buried or entombed in the church.
After the disestablishment of the Jesuits, St. Catherine's became part of the parish of St. Mark's in 1793. Since 1874, St. Catherine's has been a Collegiate church.
The church was severely damaged by the 1880 earthquake. After 6 months of repairs, it was reconsecrated in November 1881.References:
Steinvikholm Castle is an island fortress built between 1525 to 1532 by Norway's last Catholic archbishop, Olav Engelbrektsson. Steinvikholm castle became the most powerful fortification by the time it was built, and it is the largest construction raised in the Norwegian Middle Ages.
The castle occupies about half of the land on the rocky island. The absence of a spring meant that fresh water had to be brought from the mainland. A wooden bridge served as the only way to the island other than boat. Although the castle design was common across Europe in 1525, its medieval design was becoming obsolete because of the improved siege firepower offered by gunpowder and cannons.
The castle was constructed after Olav Engelbrektsson returned from a meeting with the Pope in Rome, presumably in anticipation of impending military-religious conflict. As Archbishop Engelbrektsson's resistance to the encroachment of Danish rule escalated, first with Frederick I of Denmark and his successor Christian III of Denmark, Steinvikholm Castle and Nidarholm Abbey became the Catholic Church's military strongholds in Norway. In April 1537, the Danish-Norwegian Reformation succeeded in driving the archbishop from the castle into exile in Lier in the Netherlands (now in Belgium), where he died on 7 February 1538. At the castle the archbishop left behind St. Olav's shrine and other treasures from Nidaros Cathedral (Trondheim). The original coffin containing St. Olav's body remained at Steinvikholm until it was returned to Nidaros Cathedral in 1564. Since 1568 St. Olav's grave in Nidaros has been unknown.
From the 17th to 19th century, the island was used as a quarry and some of its masonry was sold and removed from the site. This activity was condoned by the Danish-Norwegian authorities as a way of eliminating a monument to the opposition of the Danish–Norwegian Union.
Steinvikholm fort is owned and operated today by The society for the Preservation of Norwegian Ancient Monuments. The island has been the site of the midnight opera which details the life and struggles of the archbishop. The opera is held in August annually. The opera is organized by Steinvikholm Musikkteater since the beginning in 1993.