This task is about creating an unanswerable question based on a given passage. Construct a question that looks relevant to the given context but is unanswerable. Following are a few suggestions about how to create unanswerable questions:
(i) create questions which require satisfying a constraint that is not mentioned in the passage
(ii) create questions which require information beyond what is provided in the passage in order to answer
(iii) replace an existing entity, number, date mentioned in the passage with other entity, number, date and use it in the question
(iv) create a question which is answerable from the passage and then replace one or two words by their antonyms or insert/remove negation words to make it unanswerable.

Example input: Passage: In 1763, Spain traded Florida to the Kingdom of Great Britain for control of Havana, Cuba, which had been captured by the British during the Seven Years' War. It was part of a large expansion of British territory following the country's victory in the Seven Years' War. Almost the entire Spanish population left, taking along most of the remaining indigenous population to Cuba. The British soon constructed the King's Road connecting St. Augustine to Georgia. The road crossed the St. Johns River at a narrow point, which the Seminole called Wacca Pilatka and the British named "Cow Ford", both names ostensibly reflecting the fact that cattle were brought across the river there.
Example output: Who owned Cuba after the Eight Years War?
Example explanation: This question appears to be relevant to the passage as both involves words such as 'Cuba' and 'War' which also exist in the passage. The passage mentions that "after the war, almost the entire Spanish population left, taking along most of the remaining indigenous population to Cuba". This information is not sufficient to conclude that which country owned cuba.
Q: Passage: By 1836, the Duchess's brother, Leopold, who had been King of the Belgians since 1831, hoped to marry his niece to his nephew, Prince Albert of Saxe-Coburg and Gotha. Leopold, Victoria's mother, and Albert's father (Ernest I, Duke of Saxe-Coburg and Gotha) were siblings. Leopold arranged for Victoria's mother to invite her Coburg relatives to visit her in May 1836, with the purpose of introducing Victoria to Albert. William IV, however, disapproved of any match with the Coburgs, and instead favoured the suit of Prince Alexander of the Netherlands, second son of the Prince of Orange. Victoria was aware of the various matrimonial plans and critically appraised a parade of eligible princes. According to her diary, she enjoyed Albert's company from the beginning. After the visit she wrote, "[Albert] is extremely handsome; his hair is about the same colour as mine; his eyes are large and blue, and he has a beautiful nose and a very sweet mouth with fine teeth; but the charm of his countenance is his expression, which is most delightful." Alexander, on the other hand, was "very plain".
A:
The Dutchesses brother Leopold was the Queen of what country?