The Gvozdansko fortress was located on Zrinska mountain in the valley of the Žirovac stream, on the road leading from Glina to Dvor na Uni. Along with Zrin and several other nearby forts, it belonged to the powerfull Zrinski family. This area was rich in ores so that Zrinski had silver and lead mines here, and from 1525 in the time of Nikola III. Zrinski here there is a smelter, foundry and mint of coins. Here are beautiful examples of denars, groschen and thalers that testify not only to the quality of workmanship, but also to the exceptional skill of engraving. Annually, Zrinski managed to produce 700-800 kilograms of silver from the mines in the area.
Gvozdansko was first mentioned in 1488. According to descriptions and drawings from that time, we know that Gvozdansko was an exceptional example of fortification construction at the beginning of the Renaissance and one of the most valuable monuments of Croatian feudal history. During this period, defensive towers and other fortifications were built, specially designed for defense against Ottoman cannons. That is how Gvozdansko was built. The fort was entered through a square tower. At each corner stood a circular tower, while inside the fort was a palace. The fort had three floors. The defense tower was 16 meters high and stood a little more prominent than the rest of the fort.
Gvozdansko became endangered by the Ottomans when the fortress of Novigrad (today’s Dvor na Uni) fell in 1556. Namely, through the valley of Žirovnica, the old military road led to the west, which was now undefended and open to the Turks. Soon Gvozdansko came under attack. As early as 1561, the infamous Malkocs beg besieged the fort twice, but was repulsed both times. Malkocs’s attempts were continued by Ferhad beg Sokolović also on two occasions in 1574 and 1576. Each time, Gvozdansko’s crew repulsed the attacks in dramatic circumstances and managed to keep the fort. Ferhad Pasha Sokolović was a native of Bosnia and often ravaged Dalmatia. In 1577, he became a Bosnian sanjakbeg, so he increasingly attacked other parts of Croatia, and in the same year he embarked on a large military campaign aimed at capturing Gvozdansko and surrounding forts.
Already during the summer, the Turkish army built a bridge over the Una River near Novigrad, over which seven large cannons and siege devices passed. Ferhad beg led an army of about 10,000 soldiers on this military campaign. On October 3, 1577, the Ottomans blocked all roads to Gvozdansko. After that, they begin to gradually conquer the surrounding strongholds. Zrin fell on October 20 of the same year, and soon other smaller fortifications in the area.
There were about 300 defenders in Gvozdansko, but only about 50 professional soldiers, while the rest were peasants from the surrounding villages who took refuge in the fort and some nearby miners. As many as four brave captains commanded the defense: Damjan Doktorović, Juraj Gvozdanović, Nikola Ožegović and Andrija Stipšić.
After a three-month blockade, at the end of December, Ferhad beg and his army came under Gvozdansko, where the crew was already without food and woods. Namely, the war season at that time usually began in the spring when the grass for horses and draft cattle grew, and would end with the arrival of winter when there was no more food for the animals and then the armies would retreat to the winter quarters until next spring. Unusually, Ferhad beg, wanting to finally conquer the Croatian fortifications that prevented him from penetrating deeper, extended the war season, so the blocked defenders failed to prepare for the coming winter.
Until then, the crew, despite all difficulties, refused all offers to surrender, and equally rejected the offer of Ferhad beg himself, which he sent them on Christmas Day, December 25, 1577 when most of the Turkish army encamped around the city. Then the Turks started beating the fortress with cannons. The crew, considerably thinner by artillery fire and completely starved continued to reject the Turkish ultimatums, and gradually ate the guard dogs one by one. The winter was extremely cold. They say the trees were cracking from the cold. Soldiers and horses were dying frozen alive. On January 9, 1578, the crew was left completely without food, as the Turks shot poisoned meat with arrows and poisoned the last two dogs with it. In the next three days Ferhad beg organized three large raids to capture the fort, but without success.
On the morning of the fourth day, January 13, 1578, after artillery preparations, the Ottomans launched a new assault, but there was no response from the defenders. When they broke through the gates of the fortress without any resistance, they were surprised by the horrible sight. In a city full of rubble, only dead bodies were found. All the defenders lay in their positions frozen and dead, and there was no food, no water, no ammunition, no firewood in the city. This scene shook Ferhad-beg himself, who was amazed by the courage of the crew, who preferred to perish rather than surrender. Respecting their heroism, he ordered that a Catholic priest be brought in to be buried according to the Christian rite.
The fall of Gvozdansko opened the way for the Ottomans to further penetrate deeper into Croatia, which would continue until 1593 and defeat at the Battle of Sisak. The conquered Croatian lands became deserted because the population fled to the north in fear. By the end of the 16th century, a kind of balance of power was established on the battlefield, and the defense was consolidated, but even in such circumstances, the danger of Turkish incursions into Croatian lands would continue for a long time.