The rifts in the quarrelsome Georgian royal family will be laid bare as a letter to George III goes on display for the first time ever at Buckingham Palace.
In the message, the king's father - Frederick, Prince of Wales - warns him to avoid war, lower interest rates and distrust "flatterers, courtiers and ministers".
But Frederick credits his grandfather, George I, for these ideas to "retrieve the glory the glory of the Throne" rather than his father, George II - highlighting the antipathy he felt towards his own parents.
Frederick writes in the letter, which has never been on public display before: "The sooner you have an opportunity to lower the interest, for God's sake, do it... if you can be without war, let not your ambition draw you into it...
"Flatterers, Courtiers or Ministers, are easy to be got, but a true Friend is difficult to be found... Let your steadiness retrieve the glory of the throne."
The letter is a key piece in an exhibition in the Queen's Gallery to mark the 300th anniversary of the start of the Georgian era in 1714.
The bad blood between Frederick and his father dated back to when he was left behind at the family's German realm of Hanover at the age of seven.
After spending 13 years separated from his oldest son, George II favoured Frederick's younger brother William, Duke of Cumberland.
Their mother, Queen Caroline, despised Frederick's relaxed manner and after he moved to London she is reported to have said: "Popularity always makes me sick, but Fretz's popularity makes me vomit."
Familial strife was a common theme during the reigns of George I and George II.
The first Hanoverian king to rule over Britain exiled his wife Sophia for adultery and in 1717 expelled his son, the future George II, from St James's Palace after an altercation at a christening.
In turn, Frederick fell out spectacularly with his parents in 1737 when he arranged for his first daughter to be born at St James's Palace rather than Hampton Court, as had been decreed
He was publicly forced to leave St James's Palace in front of jeering crowds and, although he reconciled with his father in 1742, the relationship remained cold.
When he died unexpectedly in 1751 the throne passed to his son, George III.
Exhibition curator Desmond Shawe-Taylor said: "Surprisingly, for a family with two separate lands to rule and many divisions amongst themselves as to how it should be done, the reigns of George I and George II were very successful, firmly setting the monarchy on an unbroken line of succession to the present day.
"During the reigns of the first two Georges, Britain became the world's most liberal, commercially successful, vibrant and cosmopolitan society. This is a remarkable legacy."
The First Georgians: Art & Monarchy 1714-1760 will run from April 11 to October 12.
A BBC Four series called The First Georgians: The German Kings Who Made Britain, presented by Lucy Worsley, will be broadcast in April.