His father was killed in 1455 at the First Battle of St Albans.When his eldest brother, Henry Beaufort, 3rd Duke of Somerset, was killed fighting for Lancaster in 1464 at the Battle of Hexham, the next brother, Edmund, succeeded to the Dukedom, and John became "Marquess of Dorset" and "Earl of Dorset", courtesy titles granted to the Beaufort heir-apparent or heir-presumptive. These titles were not recognized by King Edward IV, of the House of York. John had been in exile since 1461, first in Burgundy and then France. When Henry VI of Lancaster reclaimed the throne in October 1470, John returned with his brother Edmund. But a few months later, Henry was driven from the throne again, and the Lancastrians were on the run.