The Crown season 4 is truly action-packed. In this season Prince Charles meets his future bride Diana Spencer and Lord Louis Mountbatten Prince Philip's uncle and father figure to Prince Charles, known as "Uncle Dickie" killed in an explosion.

Louis Francis Albert Victor Nicholas Mountbatten known as Lord Mountbatten or "Dickie", is the uncle of Philip, Duke of Edinburgh, and grandfather of Prince Charles. Lord Mountbatten was reportedly an “honorary grandfather” to his nephew Prince Philip’s offspring, including Prince Charles. Prince of Wales Prince Charles once said of his great-uncle ‘Dickie’: “I admire him almost more than anybody else I know.”

In the show, Lord Mountbatten pens a sternly-worded letter to great-nephew Prince Charles just hours before his death. In the letter (delivered after his assassination), he details why Charles must get over his infatuation with Camilla Parker Bowles and instead marry someone more suitable.

Lord Louis Mountbatten, born in 1900, was a high-ranking British naval officer who served during World War II and later became the last Viceroy of India, tasked with withdrawing the waning British Empire from an emerging independent India.

As the brother of Princess Alice and the uncle of Prince Philip, it was Mountbatten who introduced Prince Philip to his future wife, a young Elizabeth II, years before she was crowned the Queen of England.

Mountbatten enjoyed a close relationship with Prince Philip, acting as a surrogate father to his nephew, but it was Prince Charles whose life he shaped the most powerfully, acting as a mentor and confidante to the future king.

It was Mountbatten’s tenure in the Royal Navy that inspired Prince Charles to join the Royal Air Force, where he would perform six years of active service. Though Mountbatten was Prince Charles’ great-uncle, Prince Charles referred to him affectionately as his “honorary grandfather,” calling on him often for advice about everything from leadership to romance.

Lord Louis Mountbatten was assassinated by the Irish Republican Army (IRA), a paramilitary organization that fought against British rule in Northern Ireland, most famously during The Troubles (1968-1998). Mountbatten had been a target of the IRA for decades before his death, and in 1978 a sniper attempted to shoot him at sea but was thwarted by bad weather.

In 2015, Charles visited the Sligo spot where Mountbatten was killed, and reportedly told a well-wisher: “It’s been a long time, I never thought it would happen.”

Future King Prince Charles also spoke of his "deep loss" during a speech he gave at a local arts center, Prince of Wales said "I could not imagine how we would come to terms with the anguish of such a deep loss since, for me, Lord Mountbatten represented the grandfather I never had,"