Miguel Samuel Spiro was born in Hydra Island, Greece. He emigrated to Buenos Aires with his two brothers in 1810, and was an early supporter of the May Revolution that year.
He had been a Navy Captain in Greece, and took part in organizing the fledgling naval forces of the United Provinces of South America.
Spiro died on 28 March 1814 during a naval battle near Concepción del Uruguay (Combat of Arroyo de la China), when he decided to scuttle his ship rather than surrender to the enemy.
The Argentine navy has named two ships in his honor, the most recent being the corvette ARA Spiro (P-43), commissioned in 1988.