Europe was, for a long time, the most powerful continent on Earth. From the 16th to the 20th centuries European nations governed parts of the Americas, Africa, Oceania, and a good part of Asia too.
Europe though, was the victim of its own success. The scientific and industrial advances which had begun on the continent created terrible weapons which were unleashed in two world wars - both centred on Europe. The destruction caused brought an end to Europe's dominance, and in the aftermath the United States of America and the Soviet Union stepped into Europe's shoes as the most powerful nation's on Earth.
Unlike other states, citizenship is not granted to those born in the Vatican City; instead it is given to those appointed to work for the Holy See.
The flag of the Vatican City is one of only two national flags which are square, the other being that of Switzerland