History of Estonia between 1800 BC - 501 BC
The beginning of the Bronze Age in Estonia is dated to approximately 1800 BC. The development of the borders between the Finnic peoples and the Balts was under way. The first fortified settlements, Asva and Ridala on the island of Saaremaa and Iru in the Northern Estonia began to be built. The development of shipbuilding facilitated the spread of bronze. Changes took place in burial customs, a new type of burial ground spread from Germanic to Estonian areas, stone cist graves and cremation burials became increasingly common aside a small number of boat-shaped stone graves.
About 7th century BC, a big meteorite hit Saaremaa island and created the Kaali craters. About 325 BC, the Greek explorer Pytheas possibly visited Estonia. The Thule island he described has been identified as Saaremaa by Lennart Meri, though this identification is not widely considered probable, as Saaremaa lies far south of the Arctic Circle.
Reference: Wikipedia
Previous historical period: The Neolithic Period (-5000--1801) | Next historical period: The Iron Age (-500-1207)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.