Isabella is seen as a young girl,within a few steps of the throne; first in the care of an ambitious but unbalanced mother; later in the licentious court of her half-brother HenryIV; and at length ascending the throne, Ferdinand beside her. Meanwhile Henry IV, weak and in the hands of favourites, had married a frivolous and immoral Princess whose illicit love affair brought scandal and confusion to Castile with the birth of a child whose legitimacy was in doubt. These were momentous years in Spanish history, for here was a country in the grip of anarchy, with a royal house divided against itself. But Isabella, firm, serene and courageous, was dedicated to an idea; to bring law and order toan all-Christian Castile and to marry Ferdinand of Aragon.