Mary ( known as May) was a favourite of Queen Victoria's and she was her choice to be a future queen. She was originally betrothed to Prince Albert, eldest son of Edward VII, but he died of pneumonia shortly before they were to be married. The next year George, his younger brother, proposed to Mary and she accepted.
Their marriage seems to have been a resounding success. George wrote to her every day they were apart and unlike previous kings including his father, George never took a mistress. Such things as fidelity on the part of a royal husband that would seem a natural expectation today, weren't always the case in earlier times.
They had six children, two of whom would become kings.
George and Mary did a lot of world touring during their marriage. The Empire was far-flung and they visited every corner of the world as part of their royal duty, travelling on an unprecedented scale. They began marriage as Duke and Duchess of Cornwall and York, becoming Prince and Princess of Wales when Edward took the throne.
When Edward died in 1910, George became King. Alexandra, the dowager Queen, and Mary were often at loggerheads as both were stubborn women but there doesn't seem to be any great ill will involved. Alexandra did take her time vacating the palace after Edward's death and took with her some royal jewels that should have gone to the new Queen. But then what mother-in-law is ever perfect?
Their years on the throne were troublesome ones all across Europe. It was a time of great social change, an end for some royal houses, and of course, there was the Great War. When the Romanovs of Russia appealed to England for a safe haven, George was unable to comply. Due to serious talks of forming a republic in his own country, he couldn't risk stirring the pot. He also changed the name of the royal family from Saxe-Coburg and Gotha to Windsor, due to the strong anti-German sentiments of the time.
During this time, Mary was a strong helper and supporter of her husband and he valued her opinions. She visited hospitals and wounded during the war and took a high profile in public works.
When George became ill in the 1920s, Mary was the one who nursed him and took charge of his care. One of his doctors said that she was responsible for saving his life. George said to a speechwriter in paying tribute to his wife, "Put that paragraph at the very end, I cannot trust myself to speak of the Queen when I think of all I owe her."
George became ill again and died in 1936, succeeded by his eldest son who became Edward VIII, After less than a year Edward abdicated in favour of Bertie his younger brother who came to the throne as George VI. Queen Mary never quite forgave Edward for his abdication. She disapproved but threw her support strongly behind Bertie.
Mary lived long enough to see her granddaughter Elizabeth become Queen, though not long enough to see the coronation. For a brief time there were three living Queens in the country-Mary, George VI's widow Elizabeth known as the Queen Mum, and Elizabeth II.
Mary died in 1953.