[3][4] Francis was born in the village of Osuna, in the province of Seville, in either 1492 or 1497 (he himself was unsure), of poor peasants whose names are not recorded.
Francis himself entered military service while in his teens, in the course of which he saw action at the conquest of Tripoli (25 August 1510) by Spain under Pedro Navarro, Count of Oliveto.
Shortly after this, he set out with a friend on a pilgrimage to the great shrine of St. James the Greater at Santiago de Compostella.
He completed his studies in 1513, whereupon he received the habit of the Observant branch of the Order of Friars Minor, with the Province of Castile.
[5] This was a reform movement in the Order then becoming widespread in Spain, which sought to re-establish the primacy of prayer and poor living as practiced by their holy founder, St. Francis of Assisi.
It was an isolated house, large enough to accommodate up to 24 religious, and with five hermitages in the surrounding hills, so that one could spend up to a week in perfect seclusion.
[13] The Third Spiritual Alphabet was begun at Salceda, and probably finished at Escalona, where it is believed Osuna spent some time between 1526 and 1530; it was first published in 1527 in Toledo.