What if Catherine of Aragon (who became wife to Henry VIII OTL) was born only child ? OTL, her sister Jane the Mad became queen of Spain, but the consequences should go further : First, because Catherine was considered by her peers as brilliant and many people thought "what a shame she wasn't born a boy she would've been a great sovereign" among her hsuband's court. Second because Jane of Spain is the ancestor of Charles V and many Hapsburg sovereigns, meaning many sovereigns in general, changing the entire royal family tree of Europe. Thirdly, because Henry VIII would've had another wife, maybe one that would've granted him annulement, or would've had a surviving son with him. So, how massive would the butterflies be ? Any direct ideas ? Who would she marry ?