The village of Stare Siovo (Старе Село) is located approx. 20 kilometres southeast of Lviv, in the Lviv region, in the Pustomitskyi district of Ukraine. The settlement, located on the route of the Tatar invasions (the so-called Wallachian invasion), soon had to find its own resistance point. King Władysław II Jagiełło granted Stare Sioło to Zawisza Czarny. Zawisza's son, Jan of Garbów (also spelled Rożnow), was to build the first wooden castle in the village. Jan's daughter and Zawisza Czarny's granddaughter, Barbara, brought Stare Sióło as a dowry to Krakow castellan Jan Tarnowski, the father of the famous Great Hetman of the Crown Jan Amor Tarnowski, in 1486. Stare Sioło remained in the hands of the Tarnowskis until 1570, when, after the death of Jan Amor's daughter, Zofia, it passed into the hands of her husband, Konstanty Wasyl Ostrogski, Marshal of Volhynia and Kiev Voivode. In 1620, after the death of Prince Janusz Ostrogski, the Starosielsk estate passed into the hands of Alexander Zaslavsky, castellan of Volhynia, voivode of Braclaw and Kiev (married to Janusz's daughter, Euphrosinia). In 1629, the estate was inherited by his son Vladislav Dominik Zaslavski-Ostrogski. Subsequently, the village belonged to the Lubomirski, Sieniawski and Czartoryski families, and finally (from 1809 until World War II) to the Potocki family. The last owner was Alfred Antoni Potocki, Ordynat Łańcut.

Staryi Siole Castle is one of the largest fortresses in Ukraine. It is perched on the slope of a hill, gently sloping from the east towards a stream valley, once covered by wetlands. The lack of archaeological exploration makes it difficult to answer the question of what the oldest fortifications looked like on the site of the current castle. It is also difficult to reconstruct the shape of the new walled fortress, erected in the 1680s through the efforts of Prince Konstantin Vasily Ostrogsky. In 1642, its reconstruction was started by Władysław Dominik Zasławski-Ostrogski, who made Stare Sioło his main residence. In 1648, the still unfinished residence was destroyed by the army of Bohdan Khmelnytskyi, who was besieging nearby Lviv. The castle was rebuilt and expanded in 1649-1654, with Prince Dominik Zaslavski transforming the pre-existing structure into a magnificent defensive residence that also served as a refuge for the local population. The castle, built of brick and stone, entirely plastered, was founded on the plan of an irregular pentagon, narrowing towards the west, with five towers in the corners with loopholes and a sixth (not preserved) gate tower in the middle of the southern curtain. The north tower was particularly protruding from the castle walls. The perimeter of the walls had a length of about 500 metres, with a thickness of about 2 metres and a height of about 15 metres. The courtyard area covered more than 2 hectares. Both the towers and the walls were equipped with three levels of gun emplacements for cannons and small arms. The walls had wooden, two-storey shooting porches. The curtains were crowned by a simple arcaded attic, while the towers used richer attics with crests decorated with volutes, obelisks and spheres. The two-storey and two-bay palace was placed along the eastern curtain. On the tower, located on the axis of the palace, a stone plaque with the Leliwa and Ogończyk coats of arms and the letters W D X O Y Z W S Ł S (Wladyslaw Dominik, prince of Ostrogski and Zaslawski, Sandomierski voivode, Luck starosta) was placed. In the southern part of the spacious, almost two-hectare courtyard stood a polygonal chapel with a small, straight-closed chancel. On the southern side there was an outbuilding.

The entire building was undoubtedly impressive, both in its size and splendour. Władysław Dominik Zasławski-Ostrogski, undoubtedly one of the richest magnates of the Ukrainian lands at that time, created a residence worthy of the importance of his family. At the same time, it is known that the 3rd Ordinate of Ostrogski was an expert and patron of the arts, and had a rich library in his residence. Władysław Dominik fared much worse in the field of political bravery, and even more badly in the field of military bravery. In 1648, he was disdainfully nicknamed "the featherweight" because of his love of comforts and lack of intellectual acumen. It was Zasławski, as chief regimental officer, who was accused of leading the Polish army to a heavy defeat at the Battle of Piławce on 23-25 September 1648 through inept leadership. The castle was built according to the principles of the now obsolete bastion system, in addition to which its imposing walls and attics were a perfect target for enemy artillery. Despite this, the building coped surprisingly well during the turbulent second half of the 17th century. In 1655, the castle was not conquered by the insurgents of Bohdan Khmelnytskyi, who again besieged Lviv. In 1672, it resisted the Turks, and then Tatar attacks. The size of the castle itself must have commanded the respect of the enemy; with a large and well-trained garrison, it could have been a strong point of resistance.

Władysław Dominik Zasławski-Ostrogski died in Stary Sioły on 5 May 1656. He was succeeded by his only son, Prince Aleksander Janusz Zasławski-Ostrogski, the last male representative of the Zasławski and Ostrogski dukes' families, the Fourth Entailer of Ostrog. It is not known whether he carried out any modernisation or reconstruction work on the castle, especially as initially, due to Aleksander's minority, his mother, Katarzyna Sobieska, second voto Radziwiłł, was in charge of his estate. After Alexander's death, the Starosielsk estate including the castle passed into the hands of his sister Teofila Ludwika, married first to Prince Dmitri Jerzy Wiśniowiecki, and then to Józef Karol Lubomirski, Grand Marshal of the Crown. In the hands of the Lubomirski family, the castle deteriorated considerably as a result of the owners' lack of interest and necessary renovations. Then, with the hand of Elżbieta Helena of the Lubomirskis, the building passed to Bełz Voivode and Great Hetman of the Crown Adam Mikołaj Sieniawski. He renovated the castle and kept it in good condition and ready for battle - among other things, he supplied the castle's cechelion with new cannons, mortars and small arms. It was also during his reign that a new gate was pierced in the wall on the north-west side, and a plaque with the Leliwa coat of arms was placed above the entrance. In 1731, after his marriage to the hetman's daughter Maria Zofia, the castle became the property of August Aleksander Czartoryski. In 1809, it passed into the hands of the Potocki family. They no longer resided in Stary Siole, and used the once magnificent residence of Władysław Dominik as a brewery, distillery, warehouses and goods depots. This soon contributed to the deterioration of the building, which was further exacerbated by the establishment of a railway line nearby. By the end of the 19th century, the building was already largely in ruins. Its destruction was accelerated by the First World War, when troops were stationed in the castle, followed by the destruction of the brewery within the walls. Almost the full defensive perimeter, the ruins of the palace and four towers have survived to the present day. The chapel and the gate and western towers, which once housed the arsenal, have completely disappeared. The site is currently undergoing further degradation and urgently needs to be secured.