KnowraPortuguese succession crisis of 1580Linked fromLinked fromThe 11 pages that link to Portuguese succession crisis of 1580, each with the reason it gives.All 11Broader topic 2Related 8Compared with 1Iberian UnionBroader topic: The crisis directly produced the competing claims and military intervention that formed the union.John III of PortugalBroader topic: The extinction of John III’s direct male line helped leave Portugal vulnerable to this crisis.