Wrocław was established at the intersection of important trade routes leading from the south to the Baltic Sea and from Rus to the west. In the early Middle Ages, it was one of the most important settlements of the Ślężanie tribe. From the end of the 9th until the mid-10th century, together with the whole of Silesia, it belonged to the Czech and from about 990 it belonged to the Polish Piasts dynasty. The main element of Wrocław was then a wooden and earth stronghold at Ostrów Tumski Island, the seat of feudal and its entourage. Beside, on the also fortified borough, craftsmen and merchants lived. In 1000, Wrocław was elected the capital of the bishopric, and since 1138, was the capital of a separate land. It began to play an increasingly important role. The area of the original borough of Ostrów Tumski, too small for rapidly growing population and new foundations, was extended to the areas located in the north and on the west bank of the Odra (the Benedictine monastery was built on Ołbin, and the monastery of regular canons on the Piasek Island). On the left bank of the Odra River, a settlement of Wallonian weavers has developed. Around 1229, the first square was laid out and streets were marked out, however this lively development was interrupted by the Tatar invasion of 1241.
The destructions caused by the Mongols made the townspeople aware of the need to build defensive walls around the town, which would allow them to be protected in the future. The construction of masonry fortifications began around the middle of the 13th century, on the site of former earth ramparts with a palisade. At the latest, at the end of the 13th century, fortifications from the river side were erected. In 1291, the ditch in front of the walls was replaced at the behest of Henry V with a wide moat, irrigated with the waters of the Oława River. In 1291, the ditch in front of the walls was replaced at the behest of Henry V with a wide moat (called Black Oława), irrigated with the waters of the Oława River.
The town grew rapidly and already in the 14th century the buildings that were built outside the town walls were large enough and vast that it was decided to build, from the south and west, a new ring of walls and surround it with a moat. Works on the new circuit lasted from 1299 to 1351. The area of the New Town received fortifications from the east only in the fifteenth century. The older internal wall lost its military functions at that time. Criss-crossed by many wicket gates leading to bridges over the Black Oława (moat), it was absorbed by residential buildings. The earliest, at the beginning of the fourteenth century, this process began on the west side, where on the municipal land settlements of small houses of fishermen, wheelwrights and potters were built.
The fortification system was constantly expanded and improved as the war technics changed. With the spread of gunpowder, in the 1470s a second outer ring of fortifications with low towers was added. In the 17th century, however, bastion system was introduced in front of the old fortifications. This necessity, completely changing the appearance of the city’s foreground, resulted from the changes in fighting methods that have taken place since the late Middle Ages. The development of firearms and siege techniques, and above all the use of increasingly stronger artillery, caused that the former brick city walls lost their defensive value. After the occupation of Wrocław by Napoleon’s troops, beginning in 1807, the long process of demolishing the walls of Wrocław began.
The defensive wall of Wrocław was about six meters tall, thick for about 2 meters and topped with a battlement, which protected the defensive wall-walk. The new circuit consisted of slightly thinner walls, so that its defensive walkway had to be created on a wooden, covered porch, placed on the wall offset and supported by diagonal beams.
Defensive circuit was reinforced with numerous rectangular half towers open from the town side and extending 3.5 meters in front of wall. Such towers were used on most of the perimeter, but in the northern part of the city, on unstable grounds on the banks of the Odra and Oława rivers, the towers were in a square form and projected on both sides in front of the defensive wall axis. All probably were originally similar in height to the defensive wall and crowned with battlement. In the first half of the 14th century towers were raised, built on the side of the town and covered with a hip roofs. In the late Middle Ages a second, lower, outer wall with low towers was added. In the 15th century, the towers were 39, spaced about every 30 meters, that is, at the maximum effective shot from the crossbow. In the 1470s, construction of external fortifications began. In front of the main wall of the fourteenth century, an earth rampart and a low wall were built, reinforced by a dozen of half-round, low towers.
There were originally five town gates: Świdnicka, Nicholas, Ruska, Piaskowa (this gate was probably initially an ordinary tower, raised and equipped with a gate passage at the beginning of the fourteenth century) and Oławska. Mostly they had the shape of a gatehouse on a square plan with a lockable drawbridge. The roof was covered with shingles. After the fourteenth-century expansion of the new gates: Świdnicka, Nicholas and Oławska took over the names of the old 13th-century entrances, the auxiliary Bag Gate in the southeastern corner of the city and the modest Bricks and Odra gates were also built. From the 20s of the 15th century, gates defense was strengthened by expanding the foregates, supplying with barbicans, preparing positions for firearms. In 1479, due to fear of invasions and as a result of experience after the Hussite wars, the west Nicholas Gate was expanded by two towers surrounding the gatehouse, adapted for setting up artillery and using firearms. A similar reinforcement was also received by the Oławska Gate and in 1525 the Świdnicka Gate, protected by the largest of the Wrocław towers. The whole system was completed in 1536, at the mouth of the Bag Gate.
The outer defense zone was the moat and the Odra river from the north. It was also called Town Oława or the Black Oława and was built in the 13th century. At the turn of the thirteenth and fourteenth centuries, an external line of fortifications was marked out with a second, external moat, distant from Black Oława by about three hundred meters. Initially, the outer moat ran in the middle section slightly more to the north, while the church and monastery of Corpus Christi was located on the peninsula that was erected in front of the Świdnicka Gate.
Until today, from the once fortified strong town, only the Bear’s Tower, reconstructed in a large part, a short section of the wall next to it and two built-up external towers at the All Saints Hospital, have survived. A fragment of the defensive wall can also be seen near the Municipal Arsenal.
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