In Nov 1667 Peter II King Portugal (age 18) forced his brother to effectively abdicate King Portugal and took control.

Pepy's Diary. 13 Dec 1667. By and by comes out my cozen Roger (age 50) to me, he being not willing to be in the House at the business of my Lord Keeling (age 60), lest he should be called upon to complain against him for his abusing him at Cambridge, very wrongfully and shamefully, but not to his reproach, but to the Chief justice's (age 60) in the end, when all the world cried shame upon him for it. So he with me home, and Creed, whom I took up by the way, going thither, and they to dine with me, and pretty merry, and among other pieces of news, it is now fresh that the [his brother] King of Portugall (age 24) is deposed, and his brother (age 18) made King; and that my Lord Sandwich (age 42) is gone from Madrid with great honour to Lisbon, to make up, at this juncture, a peace to the advantage, as the Spaniard would have it, of Spain. I wish it may be for my Lord's honour, if it be so; but it seems my Lord is in mighty estimation in Spain.

Evelyn's Diary. 08 Feb 1678. Supping at my Lord Chamberlain's (age 60) I had a long discourse with the Count de Castel Mellor, lately Prime Minister in Portugal, who, taking part with his master, [his brother] King Alphonso (age 34), was banished by his brother, Don Pedro (age 28), now Regent; but had behaved himself so uncorruptly in all his ministry that, though he was acquitted, and his estate restored, yet would they not suffer him to return. He is a very intelligent and worthy gentleman.

Evelyn's Diary. 10 Jul 1685. The Count of Castel Mellor (age 49), that greate favourite and prime minister of [his brother] Alphonso, late King of Portugal, after several yeares banishment, being now receiv'd to grace and call'd home by Don Pedro the present King (age 36), as having ben found a person of the greatest integrity after all his sufferings, desir'd me to spend part of this day with him, and assist him in a collection of books and other curiosities, which he would carry with him into Portugal. Mr. Hussey (deceased), a young gentleman who made love to my late deare child, but whom she could not bring herselfe to answer in affection, died now of the same cruel disease, for wch I was extreamly sorry, because he never enjoy'd himselfe after my daughter's decease, nor was I averse to the match, could she have overcome her disinclination.