Galango was said to have been a medieval Tuscan knight, the son of a feudal lord. Galgano had a reputation for selfishness and being somewhat of a rebel in his youth. Galgano, after have a vision of the Archangel Michael, saw the error of his ways, abandoning his old life for that of a hermit at Rotonda di Montesiepi. To prove his total commitment to his new cause Galgano plunged his sword into a large stone forcing it through the rock up to its hilt, thus changing the sword into a cross a symbol of his new found piety.
For centuries the sword was thought to be a fake, but researchers revealed in 2001 that the sword is in fact, twelfth century. The University of Pavia, who tested the metal of the sword also used ground penetrating radar analysis and revealed that beneath the sword there was a cavity in which is thought to be the body of Galgano.
Incidentally, in the church, there are two mummified hands and these too are twelfth century. A local legend says that anyone who tried to remove the sword from the stone had their arms ripped off.