San Nicolás church dates back to medieval times, although it has been much altered over the centuries. It is named in the Law of Madrid of 1202 as one of the oldest parishes in the city. Today it is the oldest church in Madrid, after the demolition of the Church of Santa Maria de la Almudena. Archaeological remains suggest that the church and its bell-tower may have been part of a former mosque. It was likely constructed during the 12th century. The nave and chapels were renovated in the 17th century.
By the 19th century, this church was poor in resources and parishioners. The parish was joined to that of El Salvador in 1805. For a time, the building was abandoned till the church was ceded in 1825 to the Third Order of Servites. When the nearby church of El Salvador was destroyed in 1842, this church gained its former status as a parish church.
In the year 1891 the parish was relocated to a church that had been Anton Martin Hospital in Atocha street, today the Parish of San Nicolas and San Salvador, leaving the old building as the church of 'St. Nicholas of the Servites', a name derived from the Servite Order, which still owns it.
At the end of century profile interventions have been implemented, the main one being held in 1983. In some of these interventions was the replacement of the stone, he must be very poor, in the apse, where they appreciate different finishes to the original stone.
The most interesting feature of this temple is undoubtedly its tower, dating from the 12th century except the Herrerian style spire tops, made of slate for the 18th century. It has a square and is constructed of brick decorated with blind arches. The brick has dimensions of 30 x 15 cm in the lower parts, but it was the brick bell tower area are smaller and of a different hue. This tower possibly corresponds to one of the Arab minarets preserved in the city. The tower was transformed in the 14th century, when it changed the cover, which was subsequently replaced by the spire.
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.