Birtvisi is a ruined medieval fortress in Kvemo Kartli, Georgia, nested within limestone cliffs in the Algeti river gorge. It is now within the boundaries of the Tetri-Tsqaro municipality, adjacent to the Algeti National Park.
Birtvisi is essentially a natural rocky fortress of 1 km², secured by walls and towers, the most prominent of which – known as Sheupovari ('Obstinate') – tops the tallest rock in the area. Various accessory structures, an aqueduct included, have also survived.
In written sources, Birtvisi is first mentioned as a possession of the Arab amir of Tiflis of which he was divested by the Georgian nobles Liparit, Duke of Kldekari and Ivane Abazasdze in 1038. In medieval Georgia, Birtvisi entertained a reputation of an impregnable stronghold whose master could control the entire strategic Algeti gorge. The Turco-Mongol amir Timur notably reduced the fortress during one of his invasions of Georgia in 1403. After the partition of the Kingdom of Georgia later in the 15th century, Birtvisi was within the borders of the Kingdom of Kartli and in possession of the princes Baratashvili.References:
Château de Falaise is best known as a castle, where William the Conqueror, the son of Duke Robert of Normandy, was born in about 1028. William went on to conquer England and become king and possession of the castle descended through his heirs until the 13th century when it was captured by King Philip II of France. Possession of the castle changed hands several times during the Hundred Years' War. The castle was deserted during the 17th century. Since 1840 it has been protected as a monument historique.
The castle (12th–13th century), which overlooks the town from a high crag, was formerly the seat of the Dukes of Normandy. The construction was started on the site of an earlier castle in 1123 by Henry I of England, with the 'large keep' (grand donjon). Later was added the 'small keep' (petit donjon). The tower built in the first quarter of the 12th century contained a hall, chapel, and a room for the lord, but no small rooms for a complicated household arrangement; in this way, it was similar to towers at Corfe, Norwich, and Portchester, all in England. In 1202 Arthur I, Duke of Brittany was King John of England's nephew, was imprisoned in Falaise castle's keep. According to contemporaneous chronicler Ralph of Coggeshall, John ordered two of his servants to mutilate the duke. Hugh de Burgh was in charge of guarding Arthur and refused to let him be mutilated, but to demoralise Arthur's supporters was to announce his death. The circumstances of Arthur's death are unclear, though he probably died in 1203.
In about 1207, after having conquered Normandy, Philip II Augustus ordered the building of a new cylindrical keep. It was later named the Talbot Tower (Tour Talbot) after the English commander responsible for its repair during the Hundred Years' War. It is a tall round tower, similar design to the towers built at Gisors and the medieval Louvre.Possession of the castle changed hands several times during the Hundred Years' War. The castle was deserted during the 17th century. Since 1840, Château de Falaise has been recognised as a monument historique by the French Ministry of Culture.
A programme of restoration was carried out between 1870 and 1874. The castle suffered due to bombardment during the Second World War in the battle for the Falaise pocket in 1944, but the three keeps were unscathed.