The King's Unusual Technique: Charles III 'Sleeps in Oxygen Tent' to Relieve a Common Condition

King Charles III, who is currently battling cancer, has reportedly suffered from longtime sinus problems, according to Ingrid Seward's new book, My Mother and I. In addition to the revelation of an unusual technique the monarch uses, the tome vividly captures the decades-long relationship between Charles and his mother, the late Queen Elizabeth II.

For years, it was reported that the late monarch and her heir never saw "eye-to-eye," despite their devotion and love for one another. Elizabeth II, who became Britain's longest-reigning sovereign, came from the World War II generation, which valued duty and service above emotions and self-reflection. Seward writes about how the then-Prince Charles was "sensitive and artistic," which was said to always baffle his stoic and straightforward mother.

"The Queen never understood Charles' pampered lifestyle and found it rather mystifying, as by nature Charles is not a selfish man, but a life of being deferred to often stopped him considering others," the author revealed. "He has no sympathy for trivial ailments and combats his own sinus problems by sleeping in an oxygen tent."

Seward continued: "Tiredness or oversleeping are not acceptable excuses for missing even an hour's work, and he will never have a lie-in on a Sunday morning, even if he is feeling unwell."

The King was ridiculed for years as Prince of Wales due to his love of environmentalism and an "obsession" with spirituality that saw him labeled as a "kook" in the British press. During his legendarily fraught marriage to Diana, Princess of Wales, he even claimed once in an interview that he would "talk" to his many plants in his gardens at Highgrove House. The late princess was said to "throw his eccentricities in his face" during their many arguments in the mid and late 1980s.

On the flip side, the heir to the throne sometimes disagreed with his mother's "laid back" approach to her reign in her twilight years.

"Charles never enjoyed his mother taking part in things he thought were undignified, but even he had to admit it was a resounding success," Seward wrote. "He was, however, irritated when Angela Kelly, the Queen's dresser and later private assistant, persuaded Her Majesty to allow herself to be photographed looking like a model, with her hands in her pockets, something apparently she had always wanted to do."

"It was enough to incur Charles's wrath — he felt it was thoroughly inappropriate, however good the photographs may have been. He was protective about his mother and thoroughly disliked what he considered was taking advantage of her good nature," Seward continued.

Daily Mirror reported on excerpts from Seward's book.