Boden fortress was one of Sweden's largest military building projects of all times. It was built between 1901–1916 against the threat of Russia and consists of several major and minor forts and fortifications surrounding the city of Boden. The fortress was originally intended to stop or delay attacks from the east or coastal assaults, which at the time of construction meant Russian attacks launched from Finland. It was primarily the expansion of the railway net in Norrland, which in turn was a consequence of the rising importance of the northern iron ore fields, that led to the increased strategic value of northern Sweden and the construction of the fortress. Although the main forts were finished in 1908, many of the supporting fortifications were not completed until the start of the First World War. Improvements were also continuously made during, and between, both World Wars.
Boden Fortress is made up of five primary self-supporting forts excavated out of the bedrock in five of the mountains surrounding Boden: Degerberget, Mjösjöberget, Gammelängsberget, Södra Åberget and Rödberget. Eight fortified secondary artillery positions were constructed between the forts to give flanking support and to cover areas not in range of the main forts' artillery. In addition, 40 bunkers for infantry, along with dugouts and other fortifications, were built to cover even more terrain. During the Second World War anti-tank gun emplacements and additional bunkers and shelters were built, and tens of kilometres of dragon's teeth were placed around the fortress and the city itself. Owing to the end of the Cold War and the reduction of the threat from the Soviet Union, Boden Fortress became less important to the defence of Sweden, and began to be decommissioned. The last fort of the complex was decommissioned on 31 December 1998, and is now used as a tourist attraction. All five forts as well as some of the supporting structures have been declared historic buildings, to be preserved for the future, by the Swedish government.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.