Final answer:
Edward Mortimer, 5th Earl of March, had a stronger claim to the English throne than Henry IV based on direct descent from Lionel of Antwerp, Duke of Clarence, a senior line to John of Gaunt, from whom Henry IV descended.
Step-by-step explanation:
The question of who had a better claim to the throne than Henry IV of England can be understood in the context of the tensions and conflicts of the period. During the Hundred Years' War, which began in 1337, a crucial succession dispute arose after the French king Charles IV died without a male heir. His crown went to Philip of Valois, but Edward III of England, a nephew of Charles IV by his sister, had a potential claim by primogeniture, as he was the older claimant. Another person with a possible claim was Richard II, who was deposed by Henry Bolingbroke, later Henry IV. Henry's claim was not through direct lineage but through his father, John of Gaunt, who was a son of Edward III and acted on the pretext of acting for the good of the realm.
Edward Mortimer, 5th Earl of March, had arguably a stronger claim through direct descent from Lionel of Antwerp, Duke of Clarence, the second surviving son of Edward III, and thus senior to John of Gaunt's line from whom Henry IV descended.
The legitimacy of claims to the English throne was often complicated by competing principles of succession, which included primogeniture (inheritance by the firstborn son), proximity of blood, and, at times, parliamentary decree.