The Crown casts Natascha McElhone as Penny Knatchbull, Prince Philip's mysterious friend, for exciting new storyline

The Crown fans, get ready—Prince Philip's personal life is about to go under the microscope in its highly-anticipated fifth season. 

The Royal Family has experienced quite the analysis ever since the hit Netflix show first premiered in 2016 and, unfortunately for the Queen, it looks like the scrutiny isn't about to let up any time soon. 

The historical drama series has piqued so much interest in the British monarchy that viewers have been desperate to know just how accurate is The Crown, and if its shocking plotlines went down in reality as portrayed on-screen. 

From Princess Diana and Prince Charles' relationship to the Queen's tense relationship with her sister Princess Margaret, the Emmy-award-winning show has left few royals unscathed from dissection—and it looks like it's finally Prince Philip's turn to take the stage. 

The Crown Season Five will introduce audiences to the royal consort's inner world—focusing specifically on his relationship with Penny Knatchbull, who will be played by English actress Natascha McElhone. Described by royal biographer Ingrid Seward as "the second most important woman" in Philip's life, Penny—also known as Countess Mountbatten—enjoyed decades of friendship with the Duke of Edinburgh and remained one of his go-to confidants up until his death aged 99 in April. 

Despite never showing intimacy towards each other in public, Penny's closeness with the married Prince has been a source of speculation for years—and is likely to be treated as a steamy plotline in the upcoming season. 

Still a bit lost? Don't panic, we've rounded up the crucial facts and figures so you don't have to—starting with the woman behind the character, Natascha McElhone. 

Who is Natascha McElhone, the actor who will play Penny Knatchbull in The Crown? 

The Crown brought out the big guns to portray Penny Knatchbull, casting English actor Natascha McElhone to play the iconic character. The 51-year-old boasts an impressive resumé, having previously landed roles alongside Hollywood heavyweights Jim Carey and Robert DeNiro in blockbuster films like The Truman Show and Solaris. More recently, she played First Lady Alex Kirkman in ABC's Designated Survivor and Laz Ingram in Hulu's The First. 

Natascha's role as Penny Knatchbull will likely have her working closely with Jonathan Pryce, who will replace Tobias Menzies as Prince Philip for the fifth season. She'll also share the spotlight with Imelda Staunton, who will take over from Olivia Coleman as the Queen, and Dominic West, who will follow in Josh O'Connor's footsteps as Prince Charles. 

Who is Penelope Knatchbull, Countess Mountbatten of Burma?

Despite her lofty title, Penny Knatchbull is not royal, nor is she natively aristocratic. Born Penelope Eastwood in 1953, the 68-year-old noblewoman gained her prestigious status as Countess Mountbatten of Burma when she married British peer, Norton Knatchbull, 3rd Earl Mountbatten of Burma. With the amount of time she spends in the monarchy's company, however, it's easy to understand how fans might get confused. Penny is often spotted at high-profile royal events, even gaining an invitation to Prince Philip's scaled-back funeral last April. 

How did Prince Philip and Penny Knatchbull meet? 

Prince Philip and Penny Knatchbull go way back, having first met each other at a polo match in Great Windsor Park in 1974. The Duke of Edinburgh was reportedly smitten by the aristocratic Penny, who, at just 20, was over three decades his junior. Despite their major age gap, the two hit off after bonding over their passion for equestrianism and continued to stay in touch throughout the 80s and 90s. 

When Penny's five-year-old daughter, Leonara, died of kidney cancer in 1992, their relationship grew even tighter. Philip acted as a beacon of comfort and strength for the heartbroken mother following the devastating loss, helping her to channel her grief into the establishment of a cancer charity in memory of Leonara. 

He also offered Penny plenty of welcome relief from her sorrow, inviting her to Windsor Castle and Sandringham Estate on a regular basis to join him in his favorite pastime, carriage driving. The pair were so close that they were often spotted together at royal events—alongside the Queen, of course. 

Who is Penny Knatchbull married to? 

Penny Knatchbull married Prince Charles' second cousin, Norton Knatchbull, 3rd Earl Mountbatten of Burma, in 1979. Their wedding instantly elevated the native-born commoner's status to Lady Romsey and granted her access to the highest tier of Britain's social class—making royal minglings the norm rather than the exception. 

Penny and Norton Knatchbull have three children together, Nicholas, Alexandria, and Leonara (deceased). The couple, despite reportedly suffering marital problems throughout their relationship, will celebrate their 42nd wedding anniversary in October. Today, they live together at Broadlands, a grandiose country estate in Hampshire.