- Margaret Tudor has no children by James IV of Scotland and dies in 1512 with a stillborn boy.
- Mary Tudor the Elder goes through her OTL marriage to Louis XII in 1515. Charles Brandon then dies on his way to collect her.
- Mary Tudor the Elder then is married to John III of Portugal in 1518, after his father marries the woman he was meant to marry, Eleanor of Austria.
- Mary Tudor the Elder gives birth to 3 living children: Juan, Prince of Portugal (b.1519), Manuel of Portugal (b.1521) and Maria Manuela (b.1524).
- Mary Tudor the Younger is married to Manuel of Portugal to ensure the countries won't enter a union. Henry chooses to accept his current heir is female. They have 4 living children: Henry of Portugal (b.1536), Catherine of Portugal (b.1538), Maria of Portugal (b.1541) and Joan of Portugal (b.1544).
- Henry VIII of England fails to have another heir, marrying someone else in 1536 (perhaps an unattached Catherine of Austria, who'd be 29 and may not have found another match by the time).
- Henry VIII of England dies in 1547, leaving his only surviving child Mary as Mary I of England, flanked by her husband Manuel, Duke of Viseu.
- Juan, Prince of Portugal dies, unfortunately unmarried in 1548. His brother takes his place as heir.
- Manuel, King-Consort of England dies in 1551. His sister, Maria Manuela, has since given her husband, Philip, Prince of Asturias, only 3 stillborn girls since their union in 1543 and dies herself in 1552. This leaves Henry, Prince of Wales as King Henry I of Portugal come John III of Portugal's death in 1557.
- To gain the support of his Spanish neighbours, who attempted to claim his throne for themselves after John III's death, Henry I of Portugal marries Joanna of Austria, his senior by a year. They will have 5 living children: Anne of Portugal (b.1557), Mary of Portugal (b.1559), Henry, Prince of Portugal and Wales (b.1561), John, Duke of Beja and York (b.1562) and Catherine of Portugal (b.1565)
- Mary I of England dies, leaving her country to her only son, the King of Portugal. Henceforth, Henry I of Portugal is known as Henry, I of Portugal and IX of England.