The Queen is 'constantly frustrated' with Prince Charles as will never live up to her sense of duty, a royal expert has claimed.
In a Channel 4 documentary, royal biographer Clive Irving said that none of the Royal Family have measured up to the monarch's dedication to the job.
The author of 'The Last Queen' said Elizabeth 'never really understood' her eldest son and is 'puzzled' by him.
"To this day, she's more openly affectionate to Andrew and more forgiving toward Andrew than she is towards Charles," he added.
Charles was described as 'the polar opposite' to younger brother Andrew by Ingrid Seward, editor-in-chief of Majesty magazine.
She said: "He's [Andrew] noisy, bumptious, very charming, when he wants to be. He can be arrogant and rude; he has some characteristics of his own father."
She said that as first and second in line to the throne at that time, Charles and Andrew represented everything the monarchy could be.
The documentary, Queen Elizabeth: Love, Honour and Crown, aired on Channel 4 on Sunday night.
Show makers described it is as an 'in-depth examination of several dramatic conflicts between Crown and Family during the Queen's long reign' that also featured recently de-classified letters and documents.
It examined various important events throughout Queen Elizabeth's life, including her relationship with Prince Philip and her children.
The film begins with a look at the Queen and Prince Philip's early romance in the mid-Forties.
The programme went on to suggest that Prince Philip, 99, who is currently recovering after a month-long stay in hospital, played a key role in modernising the monarchy.
It can be viewed on Channel 4's catch up service by visiting here.
