Which European Country's Current Borders Have Remained Unchanged the Longest?

Portugal is the European country whose borders have remained officially unchanged the longest. The border between Portugal and Spain — Portugal's only land border — was established in the Treaty of Alcanizes in 1297 AD. Although certain areas within Portugal remained under Spanish control for years, the official border between the two countries has remained unchanged.

More facts about European countries:

• The oldest country established in Europe is San Marino, which established its independence in 301 AD. The newest country to establish itself is Kosovo, which declared independence in 2008.


• The smallest country in Europe is Vatican City, which has an area of about 0.2 square miles (about 0.5 square kilometers). The next smallest country, Monaco, is more than three times the size of the Holy See (AKA Vatican City) with an area of about 0.7 square miles (about 1.8 square kilometers).


• The area with the densest population in Europe is Gibraltar, a protectorate of the UK. As of 2009, Gibraltar had a population of about 31,000 people living in about 2.6 square miles (about 6.8 square kilometers) of space.