Prince Charles Edward Louis John Casimir Silvester Severino Maria Stuart (1720-1788) was the elder son of Prince James, the Old Pretender, and his wife, Princess Maria Clementina. His childhood was spent largely in the Papal States, where his father had palaces in Rome and Albano. Quarrels between his parents over the religion of his attendants made their sad mark, as did his mother's temporary departure to a convent and her early death in 1735. His life was an unhappy one. As the Stuart heir, he immersed himself in plots to regain the Throne. In 1743, his father made him Prince Regent, which effectively gave him free rein. The most direct result was the disastrous rebellion known as the Forty-Five. After its collapse, his escape made him undergo considerable privations. These tribulations conspired to turn him to alcoholism. The plots became less and less practical (for example, the Elibank plot envisaged the kidnapping of George II from St. James's Palace in the middle of London), and he became obsessed with security and vanished for long periods and argued with his family over religion. In his latter case, the casus belli was his brother's decision to be ordained a Roman Catholic priest in 1747. Charles made his own contribution to the religious problem by his conversion to the Church of England in 1750. In 1766, his father died and Charles proclaimed himself King Charles III. Unfortunately for him, his claim remained unrecognized, except by a dwindling group of supporters. The Papacy, the traditional ally of the exiled Stuarts, was only prepared to tolerate him because of the influence of his brother, Cardinal York. As a protestant with a mistress, Clementina Walkinshaw, and an illegitimate child, the Pope was not his natural ally.

His re-conversion to Catholicism in 1767 did nothing to improve his position. Surprisingly, the Government of France allowed him to gain ground despite the nasty bottle, for it was considered important to French long-term interests that Charles should marry and produce an heir. Despite the efforts of the British Government, in 1722 he married Louise, Princess of Stolberg-Gerdem, aged nineteen and settled in Florence, After an initial period of happiness, Charles began drinking heavily again in 1773. Louise put up with his behavior until 1777 when she took a lover, Count Vittorio Alfieri (1747-1803), who came a famous dramatist and poet. In 1780, the marriage broke down entirely after Charles physically attacked his wife, who then retreated to a convent, from whence she fled to Rome. Gustavus III of Sweden acted as a mediator in 1783, when Louise was given a formal separation in return for dropping financial claims.

In his last years, Charles was reconciled with his only daughter, Charlotte. He legitimized her in the French courts (while preserving his brother's right to the throne) and made her Duchess of Albany. She looked after him as he was ill with dropsy. He had a stroke and died a few days later on 31 January 1788.