Catherine of Aragon (1485–1536) was the youngest daughter of Ferdinand and Isabella of Spain. During her lifetime she wrote over one hundred letters, most of which are extant and in her hand. Her life as a writer began in 1504, two years after the untimely death of her first husband, Arthur, Prince of Wales, when she found herself isolated and impoverished due to infighting between her father and father-in-law. During these years she wrote expressive, emotional letters. In 1507 she was named ambassador from Spain to England; then, in 1509, she married Henry VIII, Arthur’s younger brother. Her letter-writing, as a result, became more conventional. In 1528, when Henry VIII sought to annul their marriage, she initiated a letter-writing campaign which became one key reason why Henry was forced to delay the annulment of his marriage by five years. After Catherine’s death, her letters were scattered in different archival libraries and rarely accessed. Only recently is Catherine’s correspondence receiving significant scholarly attention.