In 1673 a plot was discovered that intended to reinstate D.Afonso in his throne so the Regent brought him to Sintra, where he spent the rest of his life inprisionned in the royal palace until his death in 1683.
Queen D.Maria I was not exactly incarcerated but had her movements rather controlled both in Queluz and later in Rio de Janeiro, when the Court left to Brazil, where eventually she died.
George III lived his last days "in forced retirement" in Windsor Castle, unable to reign, a regency having been passed in favour of his eldest son, the future George IV .
Ferdinand I of Austria was forced to abdicate in favour of his nephew and lived in retirement in Prague.
Carlos III eldest son, Felipe Antonio, was excluded from the successions of the spanish and napolitan thrones, and abandonned by his parents when they left Naples to Madrid at the responsability of his youngest brother Fernando I.
He lived incarcerated in Naples where he died at the age of 30.
The eldest sons of Duke Roberto I of Parma by his first marriage were also mentally retarded, interned and excluded from succession.
Pr. Peter August of Saxe-Coburg-Gotha, once though to be the heir to the brazilian crown, was also mentally retarded and lived interned and was excluded from the succession.
Don Carlos, the eldest son of Felipe II of Spain, was incarcerated for the last few months of his life in the Alácazar of Madrid on the orders of his father. He was mentally unstable and violent. Rumours circulated for centuries afterwards that he was poisoned on his father's orders but there is no evidence for that.