Linked from
The 9 pages that link to Sebastian of Portugal, each with the reason it gives.
Kingdom of PortugalRelated: His death without an heir precipitated the succession crisis of 1580.
House of AvizBroader topic: His disappearance triggered the succession crisis that ended Aviz rule.
Portuguese succession crisis of 1580Related: His death without an heir opened the succession crisis.
John III of PortugalRelated: John III’s grandson inherited the crown as an infant after his death.
History of PortugalBroader topic: The crisis after his death led to the Iberian Union.