Construction of the Lausanne Cathedral began in 1170. Twenty years later another master mason restarted construction until 1215. Finally a third engineer, Jean Cotereel, completed the majority of the existing cathedral including a porch, and two towers, one of which is the current day belfry. The other tower was never completed. The cathedral was consecrated and dedicated to Our Lady in 1275 by Pope Gregory X, Rudolph of Habsburg, and the bishop of Lausanne at the time, Guillaume of Champvent. The medieval architect Villard de Honnecourt drew the rose window of the south transept in his sketchbook in 1270.
The Protestant Reformation, a movement which came from Zurich, significantly affected the Cathedral. In 1536 a new liturgical area was added to the nave and the colourful decorations inside the Cathedral were covered over. Other major restorations occurred later in the 18th and 19th century which were directed by the great French architect, Eugène-Emmanuel Viollet-le-Duc.
During the 20th century major restorations occurred to restore the painted interior decorations as well as to restore a painted portal on the South side of the Cathedral. New organs were installed in 2003.
References:The Walls of Constantinople are a series of defensive stone walls that have surrounded and protected the city of Constantinople (today Istanbul) since its founding as the new capital of the Roman Empire by Constantine the Great. With numerous additions and modifications during their history, they were the last great fortification system of antiquity, and one of the most complex and elaborate systems ever built. They were also the largest and strongest fortification in both the ancient and medieval world.
Initially built by Constantine the Great, the walls surrounded the new city on all sides, protecting it against attack from both sea and land. As the city grew, the famous double line of the Theodosian Walls was built in the 5th century. Although the other sections of the walls were less elaborate, they were, when well-manned, almost impregnable for any medieval besieger.