from an old textbook:

THE AGE OF RAPID CHANGE

Mary, daughter of the divorced Queen Catherine, had been  brought up a devout Catholic. She was thirty-seven years of  age at her accession to the throne, and had passed through  difficult times, which had left her bitter and lonely.  Mary  inherited her father's iron will, but not his physical strength.  She was sincerely convinced that her mission in life was to  bring England back to the old faith for which her mother  had suffered so much.  How could she accomplish this  tremendous task of 'setting the clock back'?  

Reigned 1553-1558

She began by releasing the imprisoned Catholic bishops,  and imprisoning Cranmer and the leading Protestant bishops.  Next she called Parliament together, and persuaded it to  annul the divorce of Queen Catherine, and to restore the  Latin mass. Parliament, however, flatly refused to give back  to the church its former lands.   

Old faith restored

Parliament also refused to support the Queen's next plan   a marriage to King Philip of Spain. The English people were  anxious enough for Mary to marry, but hoped she would  choose an English husband. Although the Tudor monarchs  had so far been friendly to Spain, times were changing.  English seamen and English merchants were beginning to  rival the Spaniards in overseas trade and exploration. English  Protestants naturally disliked the prospect of a Catholic king,  and perhaps a Catholic heir to succeed him. Lastly, there  was the fear that little England would, as a result of the  marriage, become swallowed up in the great Spanish Empire.  

Fear of Spain

In spite of a Protestant rebellion, which she crushed with  difficulty, Mary determined to go through with her plan. In  1554, Philip came to England, and the marriage was celebrated  in Winchester Cathedral. Four months later the Pope sent  Cardinal Pole to England, to act as his legate and to arrange  for the English Church to be reunited to Rome. Parliament  now repealed Henry Vlll's Act of Supremacy, and Cardinal  Pole pronounced that the English people were forgiven  for their sin in breaking away from the Pope.  

On the advice of Cardinal Pole, too, Mary revived the  law for the burning of heretics, and began to persecute those  who held to the Protestant faith. A terrible series of executions took place. In less than four years, three hundred persons were burned alive, mostly in London and the south of  England. Archbishop Cranmer was the most notable victim.  He faltered before the fiery ordeal, and confessed his heresy,  for which he asked pardon.  But when this was denied, he  met his death with great courage, thrusting his hand into the  flames ahead of him, to punish it first, for having signed the  false confession.  

Among others condemned for their Protestant faith were  two bishops, Latimer and Ridley, who were sent to the stake  at Oxford. As the flames shot up around them, Latimer com-  forted his companion with words that became famous: "Play  the man, Master Ridley!  We shall this day light such a  candle, by God's grace, in England as I trust shall never be  put out!" The English people never forgot the horror of  these executions, and for the next three hundred years  regarded all 'Papists' (as they called the Roman Catholics)  with unreasoning hatred because of them.  

In considering Mary's persecutions, we must remember  that, in the sixteenth century, nobody believed that the individual had a right to worship as he pleased. On the contrary,  it was automatically assumed throughout Christendom that  every ruler, Catholic or Protestant, had the right to make his  subjects conform to his own religion. To differ from one's  ruler, even in matters of religion, was a political offence, in  fact treason to the state. Under such circumstances, religious  toleration, as we know it today, was inconceivable. Even in  Geneva, the most advanced state in Europe at that time, John  Calvin had many of his Catholic opponents burned at the  stake.  

No freedom of worship anywhere

In Mary's case, her persecutions failed to achieve their  object.  Instead of crushing,  they strengthened the  Protestant faith, because it was bound up with growing national  feeling.  Equally unsuccessful was her marriage with Philip  of Spain, which was childless. When Mary went to war with  France, to help Spain, the only result was the loss of Calais,  England's last remaining possession on the Continent.  

Her reign therefore ended in disappointment. At her  death in 1558, the nation turned with relief, to welcome her  successor, Elizabeth, the last of Henry VIII's lawful heirs.

Loss of Calais

Richard S Lambert, The Great Heritage (1958)