Sankt Ols Kirke (St Olaf's Church), also known as Olsker Church, is a 12th century round church located in the village of Olsker. Built in the Romanesque style and reaching three storeys high, it has from the beginning consisted of a round nave, a choir and an apse.
The church was named after the revered King Olaf II of Norway who fell at the Battle of Stiklestad in 1030. The church first belonged to the Archbishopric of Lund, then came under the Danish crown at the time of the Reformation. In the 19th century, it became fully independent.
The highest of Bornholm's four round churches, rising 13 metres from its base to the top of the conical roof, the church is built of local granite fieldstone with limestone door frames. Standing on a hilltop at a height of 112 meters above sea level, it was built as a stronghold to defend the surrounding area. The openings in the wall on the upper storey were designed for shooting or throwing stones at the enemy. There was also a platform with a parapet which was used for defensive purposes. The church was also equipped with a hanging gallery, supported on beams projecting from the walls of the round tower.
The structure consists of a barrel vault and a central column bearing the upper floors. The height of the cylindrical nave, 13 metres, is almost exactly the same as that of Østerlars Church. There are small extensions from the nave into the small choir and tiny apse. The central column provides solid support for the first two storeys but is more slender in the loft where it bears the more recent roofing. The porch is probably medieval while the two buttresses to the west were added in 1825 to guard against collapse. The bell tower dates from the end of the 18th century. Restoration work was carried out in 2004 by Nils-Holger Larsen.
During restoration work in 1911 and 1950–52, frescoes were discovered in the nave and choir from at least three different periods, the oldest from the 14th century. They were however in very poor condition, especially in the nave. The early Renaissance pulpit dates from the first half of the 16th century. In the 18th century, it was decorated with paintings of the evangelists and angels. The fairly recent oak gallery is unpainted. The new organ was built by Axel Starup.References:
From its origin as a small stronghold built by the ancient Illyrian tribe Dalmatae, becoming a royal castle that was the seat of many Croatian kings, to its final development as a large fortress during the Ottoman wars in Europe, Klis Fortress has guarded the frontier, being lost and re-conquered several times. Due to its location on a pass that separates the mountains Mosor and Kozjak, the fortress served as a major source of defense in Dalmatia, especially against the Ottoman advance, and has been a key crossroad between the Mediterranean belt and the Balkan rear.
Since Duke Mislav of the Duchy of Croatia made Klis Fortress the seat of his throne in the middle of the 9th century, the fortress served as the seat of many Croatia"s rulers. The reign of his successor, Duke Trpimir I, the founder of the Croatian royal House of Trpimirović, is significant for spreading Christianity in the Duchy of Croatia. He largely expanded the Klis Fortress, and in Rižinice, in the valley under the fortress, he built a church and the first Benedictine monastery in Croatia. During the reign of the first Croatian king, Tomislav, Klis and Biograd na Moru were his chief residences.
In March 1242 at Klis Fortress, Tatars who were a constituent segment of the Mongol army under the leadership of Kadan suffered a major defeat while in pursuit of the Hungarian army led by King Béla IV. After their defeat by Croatian forces, the Mongols retreated, and Béla IV rewarded many Croatian towns and nobles with 'substantial riches'. During the Late Middle Ages, the fortress was governed by Croatian nobility, amongst whom Paul I Šubić of Bribir was the most significant. During his reign, the House of Šubić controlled most of modern-day Croatia and Bosnia. Excluding the brief possession by the forces of Bosnian King, Tvrtko I, the fortress remained in Hungaro-Croatian hands for the next several hundred years, until the 16th century.
Klis Fortress is probably best known for its defense against the Ottoman invasion of Europe in the early 16th century. Croatian captain Petar Kružić led the defense of the fortress against a Turkish invasion and siege that lasted for more than two and a half decades. During this defense, as Kružić and his soldiers fought without allies against the Turks, the military faction of Uskoks was formed, which later became famous as an elite Croatian militant sect. Ultimately, the defenders were defeated and the fortress was occupied by the Ottomans in 1537. After more than a century under Ottoman rule, in 1669, Klis Fortress was besieged and seized by the Republic of Venice, thus moving the border between Christian and Muslim Europe further east and helping to contribute to the decline of the Ottoman Empire. The Venetians restored and enlarged the fortress, but it was taken by the Austrians after Napoleon extinguished the republic itself in 1797. Today, Klis Fortress contains a museum where visitors to this historic military structure can see an array of arms, armor, and traditional uniforms.