The Spencer family home Althorp House is where the late Princess Diana not only grew up, but met King Charles, then the Prince of Wales, for the first time as he visited her sister Sarah.
However, despite its role in royal history and the fact that Earl Spencer frequently shares glimpses of the lavish estate on social media, we don't know as much about the property as we thought!
Speaking on Rabbit Hole Detectives, the podcast he co-hosts alongside historian Dr Cat Jarman and the Reverend Richard Coles, Charles revealed that although most visitors and members of the public refer to his home as Althorp, pronounced how it looks, the traditional family pronunciation is different altogether.
SEE: Charles Spencer breaks silence after Prince Harry's surprise arrival in UK
The author said: "When my father died 30 years ago, I received a letter from the BBC pronunciation department about how to pronounce my family's home name… "Is it 'al-thorp' or is it 'al-trup'?
"And to be honest, it's one of those words which, if you have two established pronunciations neither is wrong, but my grandfather called it 'al-trup', my father called it 'al-thorp'.
"The head of the BBC pronunciation department wrote to me and said, 'I hope you won't continue with that nonsense your father set and I'll hope you revert to "al-trup"' and I had to say, 'Well people round here call it "al-thorp" so can't we have both', and he didn't want both".
The dad-of-seven went on to explain that publicly, he pronounces it the way his father did because it's easier but then surprisingly added: "All my family call it 'al-trup'".
However it's pronounced, the grand property is fascinating, and Charles and his wife Karen recently shared that they have been de-cluttering the house, with some of the items set to be donated to a film and TV production company.
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