The image of Catherine of Aragon has always suffered in comparison to the vivacious eroticism of Anne Boleyn. But when Henry VIII married Catherine, she was an auburn-haired beauty in her 20s with a passion she had inherited from her parents, Isabella and Ferdinand, the joint-rulers of Spain who had driven the Moors from their country.

This daughter of conquistadors showed the same steel and sense of command when organising the defeat of the Scots at the Battle of Flodden and Henry was to learn, to his cost, that he had not met a tougher opponent on or off the battlefield when he tried to divorce her.

Henry introduced four remarkable women into the tumultuous flow of England's history; Catherine of Aragon and her daughter 'Bloody' Queen Mary; and Anne Boleyn and her daughter, the Virgin Queen Elizabeth. 'From this contest, between two mothers and two daughters, was born the religious passion and violence that inflamed England for centuries,' says David Starkey.

Reformation, revolution and Tudor history would all have been vastly different without Catherine of Aragon.

Giles Tremlett's new biography is the first in more than four decades to be dedicated entirely and uniquely to the tenacious woman whose marriage lasted twice as long as those of Henry's five other wives put together. It draws on fresh material from Spain to trace the dramatic events of her life through Catherine of Aragon's own eyes.