Mary IHistorian D.M. Loades in his 1979 biography of Mary Tudor argues that the "main legacies of her early childhood in later years were a deep attachment to her mother, and a piety as conventional as it was profound."

Henry's divorce from Katherine of Aragon affected Mary physically and psychologically. In June 1536 Henry forced Mary to accept him as "Supreme Head of the Church of England under Christ" and to repudiate "the pretended authority of the bishop of Rome." Although Henry's will reinstated Mary in the order of the succession in 1544, no attempt was made to find a suitable husband for her - either by the elder Henry or by the councilors of the young Edward VI.

Loades believes Mary was unsuited for the role of ruler.  Upon her accession, Mary appointed Stephen Gardiner Lord Chancellor, and replaced the Protestant bishops with Catholic ones. Approximately 800 English Protestants fled the country. In October 1553 Mary summoned parliament to undo the work of Edward's Protestant ministers. Parliament agreed to a statute of repeal that made the reform liturgy and the two books of Common Prayer illegal, but it would not dispense with Mary's title of Supreme Head.

In February 1554 Mary was married by proxy to Philip of Spain. The marriage treaty was very favorable to England.  Philip was to be called king and was to assist in the government, but Mary alone was to bestow and Englishmen alone to fill offices in Church and State. Philip's status as king would be cancelled if Mary died childless. Sir Thomas Wyatt, a Kentish gentlemen, led a rebellion to protest Mary's marriage to a foreign prince, but Mary's courage helped put down the rebels.

Mary's second parliament of November 1554 returned the English church to Rome, but it was agreed that monastic property would remain in private hands. A Statute of Repeals repealed all the statutes passed against Rome since the fall of Wolsey. 

In January 1555 Mary thought she was pregnant, but when her pregnancy proved to be false, Philip left England for the continent. He returned only once more - in March 1557 - to convince the English to join Spain in war against the French. 

Historians have tended to ignore Mary's successes - especially with the country's finances. She cut the sale of crown lands and the expenses of the royal household and raised the annual income from crown lands. Taxes on exports and imports were also raised so that for the first time in history the revenue from customs came to be more important than income from crown lands.