From the martyrology:
"At Granada in Spain, St. John of God, founder of the Order of Brothers Hospitallers, famed for his mercy to the poor, and his contempt of self. Pope Leo XIII appointed him as heavenly patron of the sick and of all hospitals."
St John (1495-1550) was born in Portugal, his mother died when he was only a small child, and his father joined a monastic order. As a young man, John worked as a shepherd for a farmer who was very pleased with his strength and diligent work. John had an offer to marry the farmer's daughter and become heir to the property; he refused because he wanted to pursue a spiritual life in the service of God.
He moved to Spain and became a soldier, then worked for a time disseminating spiritual works. He had a major conversion after listening to a sermon by St John of Avila, which initially saw sent to an insane asylum. He thereafter organised an Order to assist the poor and particularly the sick.