Queen Maria I "the insane" 1777-1816 Portugal In 1777 Pedro III became King of Portugal/ Maria/ his wife became Queen. When Pedro died she became the sole Ruler as Maria I. In 1796 she became mentally incompetent to rule/ thus her son Joao became Prince Regent. When the French invaded Portugal, the Royal Family fled to Brazil/ then a Colonial possession. Maria died in 1816/ so her son became King Joao VI.