ORP Błyskawica is a Grom-class destroyer which served in the Polish Navy during World War II and is the only ship of the Polish Navy awarded the Virtuti Militari medal. It is preserved as a museum ship in Gdynia, the oldest preserved destroyer in the world. It was the second of two Grom-class destroyers, built for the Polish Navy by J. Samuel White, Cowes in 1935–37. The name means Lightning. The two Groms were some of the most heavily-armed and fastest destroyers on the seas before World War II.
Two days before the war, on 30 August 1939, the Błyskawica withdrew, along with the destroyers Grom and Burza, from the Baltic Sea to Britain in accordance with the Peking Plan to avoid open conflict with Germany and possible destruction. From then on they acted in tandem with the Royal Navy's Home Fleet.
During the World War II Błyskawica took part in convoy and patrol duties in Norwegian Coast, Atlantic and Mediterranean. On 7 September 1939, Błyskawica made contact with and attacked a U-Boat, possibly the first combat between the Allied and the German fleets.
After the war, the ship returned to Poland. Since 1 May 1976, it has served as a museum ship in Gdynia.
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.