He came to England in 1545, entered the service of the crown, and was employed on the continent in some capacity which took him back to Italy. He returned to England in the reign of Edward VI, and saw service in the Scottish war under James Croft, governor of Haddington. He fought for England against the Scots at Siege of Haddington in 1548 during the war of the Rough Wooing. By coincidence, there was another Ubaldini; Migliorino, in Scotland fighting for the other side. Ubaldini then spent time in Venice, and it was not until ten years later that he settled in England, where he found a patron in Henry Fitzalan, 12th Earl of Arundel, who presented him at court. He taught Italian, transcribed and illuminated manuscripts, rhymed, and wrote or translated into Italian historical and other tracts. In 1578–9, though in receipt of a pension, he was saved from arrest for debt only by the intervention of the privy council. Ubaldini compiled an account (now lost) of the repulse of the Spanish-Italian invasion of County Kerry in 1580 (see Siege of Smerwick). He rendered into Italian in 1588 the narrative of the defeat of the Spanish Armada compiled for Lord Howard of Effingham, Commentario del successo dell' Armata Spagnola nell' assalir l'Inghilterra l'anno 1588. A free translation, as A Discourse concerning the Spanish Fleet, was made by Augustine Ryther.
He came to England in 1545, entered the service of the crown, and was employed on the continent in some capacity which took him back to Italy. He returned to England in the reign of Edward VI, and saw service in the Scottish war under James Croft, governor of Haddington. He fought for England against the Scots at Siege of Haddington in 1548 during the war of the Rough Wooing. By coincidence, there was another Ubaldini; Migliorino, in Scotland fighting for the other side. Ubaldini then spent time in Venice, and it was not until ten years later that he settled in England, where he found a patron in Henry Fitzalan, 12th Earl of Arundel, who presented him at court. He taught Italian, transcribed and illuminated manuscripts, rhymed, and wrote or translated into Italian historical and other tracts. In 1578–9, though in receipt of a pension, he was saved from arrest for debt only by the intervention of the privy council. Ubaldini compiled an account (now lost) of the repulse of the Spanish-Italian invasion of County Kerry in 1580 (see Siege of Smerwick). He rendered into Italian in 1588 the narrative of the defeat of the Spanish Armada compiled for Lord Howard of Effingham, Commentario del successo dell' Armata Spagnola nell' assalir l'Inghilterra l'anno 1588. A free translation, as A Discourse concerning the Spanish Fleet, was made by Augustine Ryther.

