Founded in 301 AD, San Marino claims to be the oldest extant sovereign state and the oldest constitutional republic.[15] It is named after Saint Marinus, a stonemason from the Roman island of Rab (in present-day Croatia), who is supposed to have established a monastic community on Monte Titano. The country has a rare constitutional structure: the Grand and General Council, a democratically elected legislature, selects two heads of state, the Captains Regent, every six months. They are chosen from opposing political parties, and serve concurrently with equal powers and preside over several institutions of state, including the Grand and General Council. Only the Federal Council of Switzerland also follows that structure, except with seven heads of state, and different responsibilities and functions.

San Marino is a member of the Council of Europe and uses the euro as its official currency, but is not part of the European Union. The official language is Italian. Its economy is based on finance, industry, services, retail, and tourism, and it ranks among the wealthiest countries in the world by GDP (PPP) per capita.[6] San Marino was also the first existing state to abolish the death penalty[16] and currently ranks 43rd on the Human Development Index.[17]