Saint Marinus holding hammer and chisel, ostrich feathers and towers at left, all within circle.

Saint Marinus was the founder of a chapel and monastery, in 301. From this initial community the state of San Marino later grew.

Tradition holds that he was a stonemason by trade who came from the island of Rab, on the other side of the Adriatic Sea (in what is now part of modern Croatia, but then part of the Roman Empire), fleeing persecution for his Christian beliefs in the Diocletianic Persecution. Still known only by the single name Marinus (lit. of the sea), he became a Deacon, and was ordained by Gaudentius, the Bishop of Rimini; later, he was recognised and accused by an insane woman of being her estranged husband, so he quickly fled to Monte Titano to build a chapel-monastery and live as a hermit. There he built a chapel and monastery.

Saint Marinus receiving Mount Titano within circle.

Monte Titano ("Mount Titan") is a mountain of the Apennines and the highest peak in San Marino. It stands at 739 m (2,425 ft) above sea level and is located immediately to the east of the capital, San Marino.

Another version of Saint Marinus's story says that he began preaching to Christian slaves at Rimini, but soon became distracted from the evil of the world. Marinus decided to seclude himself on Mount Titano, living the life of a hermit in holy contemplation. As Marinus's reputation for his sanctity grew, others started to follow him there, until finally a lady from Rimini and the owner of Mount Titano decided to gift him the mountain.