Founding of San Marino

Date: September 3, 301 • Location: San Marino, San Marino

San Marino, one of the smallest nations in the world and the world's oldest republic still in existence, is founded by Saint Marinus. San Marino, officially the Republic of San Marino, is a landlocked country in Southern Europe, completely surrounded by Italy. Located on the northeastern slopes of the Apennine Mountains, it is the larger of two microstates within the Italian Peninsula, the other being Vatican City. San Marino is the fifth-smallest country in the world, with a land area of just over 61 square kilometres (24 sq mi) and a population of 34,042 as of 2025 which in 2026 dropped to 33,559. Its capital, the City of San Marino, sits atop Monte Titano, while its largest settlement is Dogana, in the municipality of Serravalle. San Marino claims to have been founded in AD 301 and to be the oldest extant sovereign state, and the oldest constitutional republic. It is named after Saint Marinus, a legendary stonemason from the Roman island of Rab, who is said to have fled persecution under Emperor Diocletian to have established a monastic community on Monte Titano, where he built a small chapel.