Queen took her role "very, very seriously" — but some critics see a troubling history

As the world mourns the death of Queen Elizabeth II, it feels nearly impossible to imagine a change to the monarchy after her 70-year reign.

But at the time of her birth, Princess Elizabeth Alexandra Mary Windsor was never meant to be queen.

When King George V, Elizabeth's grandfather, died in 1936, his first-born son King Edward VIII ascended to the throne.  But a controversial romance with American divorcee Wallis Simpson put an abrupt end to a reign that lasted just 325 days.

"Divorce was still something that was not done. And it certainly wasn't a common practice for a monarch," royal historian Laura Mayhall told CBS News national correspondent and anchor Vladimir Duthiers.

He was given a choice: give up the love of his life or give up the throne. He chose love. His decision thrust his brother and Elizabeth's father, George VI, into the spotlight.

George VI was a man with a stutter, a fear of public speaking with no desire to be king. His life was depicted in the 2010 movie, "The King's Speech."

But he forged ahead, fulfilling his duty and preparing Elizabeth to one day be queen. That included serving in the women's branch of the British army during World War II.

The 25-year-old heir was touring Kenya when she learned her father had died and that she was queen.

"It is very clear that she understood her life would be dedicated to service," Mayhall said. "She took it very, very seriously."

But her reign did not come without controversy. There was opposition to the colonial subjugation of the Commonwealth's lands and people.

"Even under her reign, there was the Mau Mau rebellion of Kenya, for instance ... under the British at that time, which the British violently crushed, put Kenyans into concentration camps, evidence of torture of displacement which, to this day, the survivors and the descendants are seeking damages from the U.K. for that," Washington Post columnist Karen Attiah said.

In her global travels, Queen Elizabeth II never publicly acknowledged the monarchy's often brutal colonial past.  Over the past few days, many people around the world have expressed resentment toward the woman who symbolized to them the systems of oppression and forced extraction of labor.

"The reason we haven't been able to have proper conversations about Britain, about the royal family, about the symbols of white supremacy and colonialism is because those discussions have been whitewashed, erased and sabotaged," Attiah said.  Despite the complicated history of the monarchy, to many, Queen Elizabeth II was a beloved monarch — evidenced by the people all over the world who made their way to England to pay their respects to the queen who always said she was merely a humble servant.

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