Memorial of the battle of Crécy (26 August 1346) was built in the place of a windmill where the king of England waited for the attack of the king of France. The battle of Crécy was one of the most important battles of the Hundred Years' War because of the combination of new weapons and tactics used. The English knights knew the importance of being willing to fight dismounted elbow to elbow with the pikeman and archers, a procedure which was learned from the earlier Saxons and also by their battles with the Scots from whom they learned tactical flexibility and the adaptation to difficult terrain. All of these factors made Edward III's army powerful, even when outnumbered by the French forces.
The size of the forces are not known exactly. Some historians have agreed on estimates of around 10,000–15,000 on the English side and 20,000–25,000 on the French side. The battle ended to the decisive English victory. At least 2,000 French knights and unknown number of common soldiers died. The English army lost only 100-300 men. Due the victory Calais became an exclave of England. It shook France to the core and established an English presence in France that was to last for over one hundred years.
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.