In 1459 Duke Frederick married his second wife, Battista, daughter of Alessandro Sforza, Lord of Pesaro. Their portraits, painted by Piero della Francesca, are to be seen in the Uffizzi at Florence. Some years earlier, Frederick lost his right eye and had the bridge of his nose broken in a jousting match outside the town-gate of Urbino. After this accident, he preferred to be represented in profile--the profile so well known to students of Italian art on medals and basreliefs. It was not without medical aid and vows fulfilled by a mother's self-sacrifice to death, if we may trust the diarists of Urbino, that the ducal couple got an heir. In 1472, however, a son was born to them, whom they christened Guido Paolo Ubaldo. He proved a youth of excellent parts and noble nature--apt at study, perfect in all chivalrous accomplishments. But he inherited some fatal physical debility, and his life was marred with a constitutional disease, which then received the name of gout, and which deprived him of the free use of his limbs. After his father's death in 1482, Naples, Florence, and Milan continued Frederick's war engagements to Guidobaldo. The prince was but a boy of ten. Therefore these important _condotte_ must be regarded as compliments and pledges for the future. They prove to what a pitch Duke Frederick had raised the credit of his state and war establishment. Seven years later, Guidobaldo married Elisabetta, daughter of Francesco Gonzaga, Marquis of Mantua. This union, though a happy one, was never blessed with children; and in the certainty of barrenness, the young Duke thought it prudent to adopt a nephew as heir to his dominions. He had several sisters, one of whom, Giovanna, had been married to a nephew of Sixtus IV., Giovanni della Rovere, Lord of Sinigaglia and Prefect of Rome. They had a son, Francesco Maria, who, after his adoption by Guidobaldo, spent his boyhood at Urbino.