his relationship with the Beauforts varied. In his youth, he seems to have been close to all of them, but rivalries with Henry and Thomas Beaufort proved problematic after 1406. Ralph Neville, 4th Baron Neville, married Henry's half-sister Joan Beaufort. Neville remained one of his strongest supporters, and so did his eldest half-brother John Beaufort, even though Henry revoked Richard II's grant to John of a marquessate. Thomas Swynford, a son from Katherine's first marriage, was another loyal companion. Thomas was Constable of Pontefract Castle, where Richard II is said to have died. Henry's half-sister Joan was the mother of Cecily Neville. Cecily married Richard, 3rd Duke of York, and had several offspring, including Edward IV and Richard III, making Joan the grandmother of two Yorkist kings of England. Relationship with Richard II Henry experienced a more inconsistent relationship with King Richard II than his father had. First cousins and childhood playmates, they were admitted together as knights of the Order of the Garter in 1377, but Henry participated in the Lords Appellants' rebellion against the king in 1387. After regaining power, Richard did not punish Henry, although he did execute or exile many of the other rebellious barons. In fact, Richard elevated Henry from Earl of Derby to Duke of Hereford. Henry spent the full year of 1390 supporting the unsuccessful siege of Vilnius (capital of the Grand Duchy of Lithuania) by Teutonic Knights with 70 to 80 household knights. During this campaign, he bought captured Lithuanian women and children and took them back to Königsberg to be converted, despite Lithuanians being baptised by Polish priests for a decade at this point. Henry's second expedition to Lithuania in 1392 illustrates the financial benefits to the Order of these guest crusaders. His small army consisted of over 100 men, including longbow archers and six minstrels, at a total cost to the Lancastrian purse of £4,360. Despite the efforts of Henry and his English crusaders, two years of attacks on Vilnius proved fruitless. In 1392–93 Henry undertook a pilgrimage to Jerusalem, where he made offerings at the Holy Sepulchre and at the Mount of Olives. Later he vowed to lead a crusade to 'free Jerusalem from the infidel', but he died before this could be accomplished. The relationship between Henry and the king met with a second crisis. In 1398, a remark regarding Richard II's rule by Thomas de Mowbray, 1st