His Royal Highness Charles, Prince of Wales, has famously been the longest-serving heir apparent in British history. He was just 3 years old when his grandfather, King George VI, died and his mother, Queen Elizabeth II, ascended the throne for her historic reign as the longest-serving monarch in not only British, but world history. But for all the very public events of the prince's life that have played out on the world's stage (his marriage to and divorce from Princess Diana; his decades-long relationship with Camilla, Duchess of Cornwall; his oft-strained relationship with his father), he has spent years working behind the scenes to promote charities and fulfill his duties as a leading member of the royal family. And he even finds time to do some landscape painting. Here are nine things you might not know about Prince Charles.

1. HE WAS THE FIRST ROYAL BABY BORN AT BUCKINGHAM PALACE IN THE 20TH CENTURY.

Princess Elizabeth was 22 when she gave birth to Charles Philip Arthur George on November 14, 1948 (just six days before his parents' first anniversary). Newspapers reported he was "a lovely boy, a really splendid baby," but Matthew Halton of CBC Radio reminded listeners that the newborn wouldn't be king any time soon. "If his grandfather, the King, and his mother, the princess, both live the full span of life," Halton reported, "he may well be 50 or 60 years old before he ascends the throne."

2. HE WAS 9 WHEN HE WAS OFFICIALLY GIVEN THE TITLE PRINCE OF WALES.

Though he is already the longest-serving Prince of Wales, he could have held the title for a few extra years if he'd been appointed earlier. The title "Prince of Wales" is only given to a male heir apparent, but it is not an automatic appointment. Charles went from third to second in line to the throne when his grandfather died in 1952, but it wasn't until 1958, when he was 9 years old, that he was granted the title Prince of Wales and its conjoining title, Earl of Chester.

3. THERE'S A CHANCE HE COULD CHANGE HIS NAME WHEN HE TAKES THE THRONE.

Many monarchs choose a regnal name (as popes do) that is different than their birth name, such as Charles's grandfather George VI, who had been christened Albert Frederick Arthur George and went by Bertie for most of his life. And though the prince has been the most famous Charles in the UK for seven decades, the previous two King Charleses did not go down well in British history. Charles I was executed for treason and the monarchy was briefly abolished because of his actions; his son, Charles II, spent time in exile until the monarchy was restored 11 years later. He was generally beloved, but was known as a philanderer who acknowledged at least a dozen illegitimate children. And to some, Charles Stuart—best known as Bonnie Prince Charlie and for the Jacobite rebellion in Scotland that attempted to put him on the throne—was called Charles III.

According to the BBC, Charles has considered going with his third middle name and reigning as George VII, though Charles’s camp denied this, saying "No decision has been made and it will be made at the time"—meaning, after the queen’s death.

4. HE CAN PLAY THE CELLO.

Charles learned piano, trumpet, and cello as a child, and though he described himself as "hopeless," he stuck with the cello and played in the Trinity College Orchestra while in undergrad.

5. HIS SECRET SERVICE NAME IS "UNICORN."

Certain visiting dignitaries to the U.S. are given code names of their own, and Charles was given Unicorn. The fanciful name is oddly fitting—the unicorn is the national animal of Scotland and has been part of its coat-of-arms for some 600 years. But the first recorded example of a Scottish monarch using a unicorn as a symbol of strength was from the late 1300s, when either Robert II or III used unicorns as part of the arms and gateway of Rothesay Castle on the Isle of Bute, Scotland. Among Prince Charles's earliest titles, which he received at age 5, is Duke of Rothesay.

6. RICHARD NIXON TRIED TO SET CHARLES UP WITH HIS DAUGHTER TRICIA.

In 1971, President Nixon's eldest daughter, Tricia, had the first outdoor White House wedding in the Rose Garden. But the summer before, her father was trying to play matchmaker with the future king of England. Charles and his sister, Princess Anne, were 21 and 19 at the time when they took an unofficial trip to Washington, D.C. They were feted as royal dignitaries, taken to various museums and D.C.-area sites, and given rooms in the White House (Charles slept in the Lincoln Bedroom). And, according to Sally Bedell Smith's 2017 biography Prince Charles: The Passions and Paradoxes of an Improbable Life, "The president arranged to have Tricia seated next to Charles at every occasion, which annoyed him."

Even though he didn't hit it off with the First Daughter (Bedell Smith says "he would describe her, ungenerously, as 'artificial and plastic'"), Charles was still bemused by the president's endeavors. "Many years later on a visit to Washington with Camilla, he was still laughing about Nixon's attempt at matchmaking."

7. HE FIRST MET DIANA WHEN HE WAS INVOLVED WITH HER SISTER.

Charles had a playboy reputation in his twenties, and any girl with a family pedigree was considered a potential princess, and therefore media fodder. In June 1977, he met Lady Sarah Spencer at a party at Windsor Castle, and the two invited each other to polo and shooting events. That November, Charles went to the Spencer estate Althorp, where he met Sarah's younger sister. Diana was 16.

According to Bedell Smith in her 1999 biography Diana in Search of Herself: Portrait of a Troubled Princess, after going on a Swiss ski vacation with Charles in February 1978, Sarah told a tabloid that she was not falling for the prince, saying "There's no question of me being the future Queen of England. I don't think he’s met her yet."

8. HE WROTE A CHILDREN'S BOOK.

In 1980, Prince Charles wrote a children's book called The Old Man of Lochnagar, based on stories he would tell his younger brothers, Princes Andrew and Edward. It centers around an old man who went to the caves near Balmoral looking for a quiet place to take a hot bath. The book was later turned into an animated short film, narrated by the prince.

9. THERE IS A FROG NAMED AFTER HIM.

In 2012, a newly discovered (and endangered) species of Ecuadorian tree frog was announced as the Hyloscirtus princecharlesi, or the Prince Charles stream treefrog, in the journal Zootaxa [PDF]. It was named after him to recognize his rainforest conservation work—HRH has long been outspoken about the dangers of climate change, and he set up the Prince's Rainforest Project in 2007 as a charity and awareness campaign.