Netflix’s drama The Crown might be heading into its fourth season, but a couple of additions will likely draw new viewers in. Presenting: Princess Diana and Margaret Thatcher. The two are seared into the public consciousness, but the details around them might need a little shoring up before you watch them portrayed on the show.

Let’s dive into every question you might have about the British royal family and more.

Read more: What The Crown gets right (and wrong) about Princess Diana

Who are the main members of the family?

Aside from Queen Elizabeth II (Olivia Colman), season 4 follows:

• Prince Philip (Tobias Menzies), the Queen’s husband
• Princess Margaret (Helena Bonham Carter), the Queen’s younger sister
• Queen Elizabeth (Marion Bailey), the Queen’s mother
• Lord Mountbatten (Charles Dance), a British Royal Navy officer and statesman, and Prince Charles’ great-uncle
• Princess Anne (Erin Doherty), the Queen’s only daughter
• Prince Charles (Josh O’Conner), the Queen’s eldest son and the Prince of Wales
• Camilla Parker Bowles (Emerald Fennell), Prince Charles’ ex-girlfriend who married Andrew Parker Bowles
• Lady Diana Spencer (Emma Corrin), daughter of of John Spencer, 8th Earl Spencer, and Prince Charles’ future wife

What’s the IRA?

At the beginning of the season, set in 1979, Lord Mountbatten, Prince Charles’ great-uncle, is killed in a bomb attack while fishing on a boat north-west of Ireland. The IRA, Irish Republican Army, claim responsibility for the execution. The IRA was a paramilitary organization that emerged in the late ’60s, seeking to end British rule in Northern Ireland. It was designated a terrorist organization in the United Kingdom and an illegal organization in the Republic of Ireland.

Why did Prince Charles not marry Camilla?

Prince Charles and Camilla did have their time together as a couple, but their relationship ended after Charles joined the Royal Navy in 1973. While unconfirmed, the overall reason Prince Charles didn’t marry Camilla is put down to Camilla being deemed unsuitable as a wife for the future king. The pair remained friends and, after Lord Mountbatten’s death, a grief-stricken Charles relied on a now-married Camilla for solace. Eventually, they rekindled their romance and had an affair.

Why did Prince Charles marry Diana instead?

Charles met Diana when he visited the Spencer estate in 1977. He was dating her older sister Lady Sarah at the time. The two broke up and Charles pursued Diana. On paper, she had all the right attributes for marriage: daughter of an earl with royal connections and no former boyfriends with stories the tabloids would eat up. In 1981, Charles proposed to Diana, who was 20 years old at the time, and she accepted.

Who’s Margaret Thatcher?

Margaret Thatcher was the British prime minister from 1979 to 1990. She was the longest serving British prime minister since 1827 and the first woman to hold that office. Her nickname, the “Iron Lady,” came from her uncompromising politics and leadership style.

Why did Margaret Thatcher resign?

Thatcher led the Conservative Party to victory in three consecutive general elections. But after 11 years in Britain’s top office, Thatcher resigned. Basically, this was because of her poll-tax policies and opposition to further British integration into the European Community alienating some members of her party. She failed to receive a majority in the Conservative Party’s annual vote for selection of a leader. In 1990, she announced her resignation and was succeeded by John Major.

Was Princess Margaret married?

In episode 7, Princess Margaret, the queen’s younger sister, learns she can’t be with her love Derek “Dazzle” Jennings (Tom Burke) because the civil servant wants to become a Catholic priest and he’s believed to be a “friend of Dorothy” — gay. This isn’t the first time Margaret’s fallen in love. When discussing Prince Charles’ love for Camilla, Margaret refers to the crown not allowing her to marry her love Group Captain Peter Townsend. She was 22 when the divorced man 16 years her senior proposed to her. These factors contributed to the crown not approving their marriage. In 1960, Margaret married photographer Antony Armstrong-Jones, but they divorced in 1978.

Did Princess Diana really dance at the Royal Opera House?

Yes, Princess Diana really did appear on stage for a surprise dance performance at the Royal Opera House in 1985. Diana reached out to dancer Wayne Sleep and they choreographed a routine to Billy Joel’s Uptown Girl for a private event to thank the patrons who had supported the Royal Ballet. Only a few black-and-white photographs came out from the night.

What happened to Princess Diana?

At the end of the season, it’s the early ’90s, and Princess Diana and Prince Charles have two children together, Prince William and Prince Harry. But they’ve both had affairs and Prince Charles is determined to separate. Next season, we’ll likely see the events leading to the pair’s divorce in 1996 after 15 years of marriage. Following the divorce, Diana continued to be regarded as a member of the royal family, as the mother of the prince expected to one day ascend to the throne.

In 1997, Diana tragically died in a car accident in the Pont de l’Alma tunnel in Paris while the driver was fleeing the paparazzi. She was 36.

What do the real royal family think of the show?

We’ll never really know, since it’s unlikely the royal family would ever admit to watching The Crown. But according to reports from sources close to the family, they’re not the biggest fans.

Royal biographer Penny Junor told The Times of London that Charles would likely be “incredibly upset” by season 4 because of the scene where Lord Mountbatten says the royal family is disappointed in Charles’ relationship with Camilla, adding Mountbatten’s dismissal of Camilla to Charles’ face is “just not historically accurate.”