The Crown has reached the 1980s.

The fourth series of the drama which chronicles Queen Elizabeth II's reign is proving popular with millions of viewers, giving them an insight into an eventful decade in British and world history.

The 1980s saw the UK’s first ever female prime minister triumph in another two elections after taking office in 1979. A royal wedding became one of the most-watched events in history and Britain went to war against Argentina over control of the Falkland Islands.

We’ve taken a look at some of the people, places and events that feature in the latest series, and put them into an historical context.

The Queen’s meetings with Margaret Thatcher

Queen Elizabeth II has regular meetings with her prime minister to discuss the country’s affairs. Very little, if anything, is known about the conversations that take place during these private briefings.

As with previous series, The Crown will continue to depict some of these discussions. This time, they will involve Margaret Thatcher, played by Gillian Anderson, debating issues with the Queen, played by Olivia Colman. Mrs Thatcher came to power in 1979 and was the longest serving prime minister of both the 20th Century and the Queen’s reign so far.

The relationship between them has often been guessed at, and The Crown shows Her Majesty questioning some of her prime minister’s policies that led to unrest in different parts of the country. It is unlikely the truth will ever be known; Mrs Thatcher died in 2013 and the Queen rarely gives interviews.

In 1995, the Queen chose to make her former prime minister a member of the Order of the Garter, seen as one of the highest honours the monarch can give to someone. The Queen was also present at Mrs Thatcher’s funeral, one of the few she has attended in her reign.

The wedding of Prince Charles and Lady Diana Spencer

In the early months of 1981, a nursery school teacher who navigated London in a red Mini Metro became one of the most photographed people in the world. Her name was Diana.

Lady Diana Spencer (played by Emma Corrin) began dating Prince Charles (Josh O’Connor), the heir to the throne, in the winter of 1980, when she was 19 years old and he was 32. They were engaged in the spring of 1981 and married on 29 July that year. The wedding was a big celebration in the UK, where it was a national holiday. An estimated 750m people around the world watched the ceremony live from St Paul’s Cathedral.

Princess Diana went on to become one of the most famous, and written about, people on the planet. She gave birth to Prince William in 1982 and Prince Harry in 1984.

Before her death in 1997, Diana had supported charities which campaigned against landmines and homelessness, among other issues. In 1987, she also made headlines by shaking the hand of a patient who had Aids while visiting a London hospital. At that time, there was a stigma around the disease and the moment - the Princess did not wear gloves - challenged the misinformation that HIV and Aids could be transmitted through a brief, casual touch.

John O’Reilly, a nurse on the ward at the time of the visit, told the BBC’s Witness 30 years later: “If a Royal was allowed to go in and shake a patient’s hands, somebody at the bus stop or in the supermarket could do the same. That really educated people.”

Michael Fagan breaks into Buckingham Palace

On 9 July 1982, an unemployed father of four called Michael Fagan broke into Buckingham Palace and found his way into the Queen’s bedroom.

It was reported that he spent around 10 minutes speaking to her before being removed from the premises, although the facts about the encounter have never been confirmed. Trespass was not a criminal offence at the time, so Fagan did not face charges which could put him in prison. He did appear before a judge over a separate incident in October 1982, who ordered that Fagan become a patient at a psychiatric hospital, where he spent three months.

In 1984, the act of trespass, with the intention of causing disruption - or aggravated trespass, did become a criminal offence. In 2003, a member of the public gatecrashed Prince William's 21st birthday party at Windsor Castle to promote a comedy show, but no further action was taken against them. The incident did lead to calls for acts of ordinary (or non-aggravated) trespass on royal and government property to also become a criminal offence in future.

In June 2007, the Trespass On Protected Sites law was introduced. This made sixteen sites in England a ‘no-go’ for trespassers in 2007, including Buckingham Palace, Windsor Castle and 10 Downing Street. Anyone found on those sites without good reason now face up to six months in prison.

The Falklands War

This conflict was a key moment in Margaret Thatcher’s first term as prime minister. On 2 April 1982, forces from Argentina invaded the Falkland Islands, a British colony in the south Atlantic ocean.

Argentina said it had inherited the islands from Spain in the 1800s and wanted to reclaim them. The British had ruled the Islands for 150 years and armed forces were sent on an 8,000 mile journey by sea to take the islands back.

In the six weeks of battle, hundreds of people on both sides were killed. Argentina’s troops surrendered to the British on on 14 June. The victory helped boost Mrs Thatcher’s popularity at home and she went on to win the 1983 General Election by a large margin.

Apartheid in South Africa

The latest series of The Crown will show The Queen and Mrs Thatcher disagreeing about action taken against South Africa over apartheid. This was a system in place in South Africa which gave white people more rights than black people. Nelson Mandela and other activists spent many years fighting to end apartheid and ensure all people were equal. Nelson Mandela was jailed in 1962 over his political activities.

Countries and organisations took a stand against apartheid in different ways. This included the use of economic sanctions against South Africa, such as stopping oil trade, until it agreed to end apartheid. The Commonwealth countries, of which the Queen is head, also wanted to impose sanctions, but Mrs Thatcher did not want to, which caused controversy at the time. She said she preferred to negotiate with politicians in the country instead.

In 1990, Nelson Mandela was released. In 1994, he became president of South Africa, as a result of the first elections held since the end of apartheid. In the same year, South Africa regained its United Nations membership.

With no written records of the private meetings between the Queen and her prime minister, we will never know the monarch’s real view on Mrs Thatcher’s approach. The Crown’s version will no doubt entertain the series’ many fans, but we can’t, for now at least, take it as anything more than speculation.