Østerlars Church is the largest and, possibly, the oldest of the Bornholm island's four round churches. Built in about 1160, it was dedicated to St. Lawrence. It consists of an apse, an oval chancel, a large round nave and has three storeys. There is evidence the church was once fortified, the top storey serving as an open shooting gallery. The fieldstone wall stands on foundations of Bornholm limestone. The double-arched apse bears similarities to that in Lund Cathedral. The round nave has an external diameter of 16 meters. In its centre there is a large round hollow column, six meters wide. An opening, known as the oven, leads into a small room inside the column.
Originally there were small Romanesque windows but these were enlarged after the Reformation. During the 16th century, a number of pillars were added to support the outer wall. The conical roof was replaced in the 17th century. The porch is from 1870. The bell tower stands separately from the church in the churchyard, and the bell tower was the original entrance and gate tower. There are two runestones, one inside the porch (c. 1100) and another outside (c.1070).
The church's central column is decorated with frescos from 1350 showing biblical scenes from the Annunciation through to the Passion, ending with Day of Judgment where Jesus judges mankind. Many of the naked figures are sent to hell, symbolized by a huge dragon. They were probably painted some 140 years after the church was built. The frescos, which had been hidden with limewash since the Reformation, were uncovered in 1882. The pulpit is from 1595. The carved altarpiece is from c. 1600.
Erling Haagensen, co-author of The Templars' Secret Island, believes there is a connection between the round churches of Bornholm and the Knights Templar. He believes there are similarities between the geometrical precision of the churches' locations and those of churches in Rennes-le-Châteauin France. He concludes that Østerlars, and the other round churches, could have been used as supply stores for the crusades.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.