In May to September 1390 Beaufort served in Louis II, Duke of Bourbon's crusade in North Africa. In 1394 he was in Lithuania serving with the Teutonic Knights.[7][8] In 1396, after his parents' marriage, John and his siblings were legitimated by a papal bull. Early the next year, their legitimation was recognized by an act of Parliament, and then, a few days later, John was created Earl of Somerset (10 February 1397).[9] That summer the new Earl was one of the noblemen who helped Richard II free himself from the power of the Lords Appellant. As a reward on 29 September he was created Marquess of Somerset and Marquess of Dorset, and sometime later that year he was made a Knight of the Garter and appointed Lieutenant of Ireland. In addition, two days before his elevation as a Marquess he married the King's niece, Margaret Holland, sister of 3rd Earl of Kent, another of the counter-appellants.[9] He remained in the King's favour even after his half-brother Henry Bolingbroke (later Henry IV) was banished. In February 1397 he was appointed Admiral of the Irish fleet, as well as constable of Dover and Warden of the Cinque Ports. In May his Admiralty was extended to include the northern fleet.