What is the name of the person who was not seen as a viable heir to the monarchy?  Answer the above question based on the context below:  Pedro I's successor in Brazil was his five-year-old son, Pedro II. As the latter was still a minor, a weak regency was created. The power vacuum resulting from the absence of a ruling monarch as the ultimate arbiter in political disputes led to regional civil wars between local factions. Having inherited an empire on the verge of disintegration, Pedro II, once he was declared of age, managed to bring peace and stability to the country, which eventually became an emerging international power. Brazil was victorious in three international conflicts (the Platine War, the Uruguayan War and the Paraguayan War) under Pedro II's rule, and the Empire prevailed in several other international disputes and outbreaks of domestic strife. With prosperity and economic development came an influx of European immigration, including Protestants and Jews, although Brazil remained mostly Catholic. Slavery, which had initially been widespread, was restricted by successive legislation until its final abolition in 1888. Brazilian visual arts, literature and theater developed during this time of progress. Although heavily influenced by European styles that ranged from Neoclassicism to Romanticism, each concept was adapted to create a culture that was uniquely Brazilian. Even though the last four decades of Pedro II's reign were marked by continuous internal peace and economic prosperity, he had no desire to see the monarchy survive beyond his lifetime and made no effort to maintain support for the institution. The next in line to the throne was his daughter Isabel, but neither Pedro II nor the ruling classes considered a female monarch acceptable. Lacking any viable heir, the Empire's political leaders saw no reason to defend the monarchy. After a 58-year reign, on 15 November 1889 the Emperor was overthrown in a sudden coup d'état led by a clique of military leaders whose goal was the formation of a republic headed by a dictator, forming the First Brazilian Republic.
Isabel