When the US embassy moves out of Grosvenor Square, London, early next year it will be the end of a centuries-old connection with this corner of Mayfair. The first ambassador to Britain, future President John Adams, lived from 1785 to 1788 in a house that still stands on the square.
The embassy itself was housed in several central London buildings before settling into Grosvenor Square in 1938 and its current home in the 1950s. During the second world war, it was even known as “Little America”, after General Dwight D Eisenhower set up his headquarters across from the diplomats.
The US was forced out of this old home mostly by concerns about terrorism, in an era when embassies have become mini-fortresses. It was impossible to install controls that met US government standards around a building in the heart of historic London and neighbours resented growing layers of security.
The new headquarters is across the river, in a new tower in Vauxhall, its fortifications as discreet as possible in an attempt to avoid the impression of an American bunker, and including a pool that doubles as a moat and bollards hidden in yew hedges.
The effectiveness of those protections at keeping even peaceful crowds at bay may be tested as soon as next year – if President Donald Trump takes up an invitation to officially open the building. Huge crowds are expected to protest at any visit and a march would be likely to pass by or end at the embassy.
As practical and symbolic outposts of distant governments, embassies have always been destinations for protests about policy and also targets for much bloodier attacks.
In an age of US superpower, the country’s outposts have been particularly high-profile, often at the centre of seminal events in the last century. Some of the most famous embassies, and the events that unfolded in and around them, are remembered here.
Grosvenor Square, London 1968

The embassy that the US is now leaving behind, and which will become a luxury hotel, acquired worldwide fame in 1968, when a demonstration against the Vietnam war turned violent.
About 8,000 mostly young protesters had marched from a demonstration in Trafalgar Square on 17 March, accompanying the actress and activist Vanessa Redgrave, who wanted to deliver a letter to the embassy.
Protesters entered an already crowded square, contemporary reports say. More than 1,000 police were waiting, and perhaps 2,000 other spectators, including conservatives who shouted “treason” and pro-war slogans such as “Bomb, bomb the Vietcong” at the marchers.
A fierce battle broke out and raged for over an hour. Demonstrators who had broken into embassy lawns hurled mud, stones, firecrackers and smoke bombs. Police hit back, with mounted officers launching charges.
More than 80 people, police and protesters, were injured, and there were more than 200 arrests. The violence in one of London’s most staid, upmarket areas was a shocking moment in a wave of worldwide protests against the war that added to domestic pressure on US governments to leave Vietnam.
Saigon, Vietnam 1975

The picture of desperate crowds scaling a metal ladder to board a CIA helicopter leaving Saigon, captured by a Dutch photographer on 29 April 1975, became one of the defining images of the Vietnam war.
About 7,000 people, only a minority of them American, were flown out from the embassy and other sites in Saigon in the hours before the city fell. Helicopters landed amid clouds of smoke from roof-top incinerators, as officials frantically burned classified documents, and a swirl of fragments from shredded documents.
Their retreat summed up the frantic chaos of the US withdrawal and became symbolic of wider policy failings in a war that claimed the lives of millions of Vietnamese civilians and soldiers and nearly 60,000 US troops.
Not captured in the picture of the helicopter, but widely documented elsewhere, were even more desperate throngs of mostly Vietnamese civilians gathered around the embassy gates, hoping to make it out. As the North Vietnamese troops closed in, reports were circulating of mass graves in towns they had captured.
After the fall of Saigon, the embassy was closed for two decades. When diplomatic ties between the US and Vietnam were re-established in 1995, the Vietnamese capital had shifted north to Hanoi. The former embassy was handed back to the US, but the old building was demolished and the site now forms part of a park inside the grounds of the US consulate general in what is now Ho Chi Minh City.
Tehran, Iran 1979

In November 1979, the US embassy in Tehran became the centre of a drama that would transfix the world, overshadow and perhaps hasten the end of Jimmy Carter’s presidency, and poison relations with Iran for decades.
Student militants overran the embassy building and seized diplomats in an occupation originally planned to last a few days. But news of the takeover raced around Iran and the world, and even as photos of blindfolded Americans stumbling from the building sparked international outrage, it was clear that domestically the student invasion was popular.
The government took over management of the crisis from students, and although 14 hostages were released near the start of the ordeal, another 55 were held for more than a year in grim conditions. They endured solitary confinement, humiliation and even mock executions, among other privations, until they were released in January 1981, hours after Ronald Reagan became president. That timing was widely seen as one last snub to Carter from Iran.
There could have been even more people affected, but the embassy staff had been reduced to a minimal team after it was attacked and briefly occupied in February that year. Six other US diplomats who were outside the embassy when it was stormed took shelter with Canadian counterparts and were smuggled out in a daring operation dramatised in the film Argo.
The embassy building was never returned to the US. It has been turned into a museum with exhibitions on spycraft that Iran says was practised inside and a “Museum-Garden of Anti-Arrogance”. Demonstrations are held annually outside on the anniversary of the hostage-taking, with cries of “Death to America”.
Tiananmen Square, Beijing, China 1989

The day after tanks silenced the pro-democracy protests in Tiananmen Square in early June, and students fled back to their homes and dormitories, one of China’s most famous dissidents left his own university to seek refuge in the US embassy in Beijing.
Physicist Fang Lizhi and his wife, Li Shuxian, were, say reports, No 1 and No 2 on a government list of those wanted for their role in fomenting the “counterrevolutionary rebellion”. Overcoming initial concerns of its diplomats, Washington ordered the embassy to take the couple in.
They stayed on in the American embassy for nearly a year, somewhat awkward guests for an administration worried about keeping Beijing on side as an anti-Soviet ally. Diplomats worried about getting Fang out of China, but also feared the government would break international laws and mount a raid to seize him.
A respected scientist as well as a prominent intellectual, he continued publishing research while, in effect, under house arrest. He also wrote a poignant essay arguing that the uprising would soon be largely forgotten in China because of the Communist party’s control of media and education, an insight that proved largely true.
The negotiations to get the couple out of China eventually involved Henry Kissinger, the seasoned US diplomat, and the Japanese government, which promised to restart loans if the “Fang Lizhi problem was solved”. He was flown to the US, where he spent the rest of his life.
Nairobi, Kenya, and Dar es Salaam, Tanzania 1998

The US embassies in the Kenyan and Tanzanian capitals were devastated by near simultaneous truck bombs on the morning of 7 August. The attacks killed 224 and injured more than 4,000, and remain the bloodiest peacetime attacks on any US mission.
They also brought the name of an ambitious Saudi exile – Osama bin Laden – and his terrorist group al-Qaida to the attention of both the wider US public and Islamist militants around the world.
Bin Laden had previously been linked to a suicide attack on the guided-missile destroyer USS Cole. But after the devastation in east Africa, US authorities put up a $5m award for information leading to his arrest and added him to their “most wanted” list.
The attacks had been planned meticulously and their scale, sophistication and violence surprised US intelligence, the New Yorker reported. Although the targets of both attacks were the respective US embassies, the vast majority of the victims were Kenyans. The Nairobi blast collapsed a neighbouring building and the heat from the explosion was channelled down a narrow alley, incinerating a bus full of commuters.
The Nairobi embassy had received a warning of the attack and the ambassador had tried to move to safer premises, it was later revealed.
The bombings ushered in a new era of defences and fortifications, with even US missions far beyond war zones ramping up protections. The Nairobi embassy was moved to a safer location.
Benghazi, Libya 2012

On 11 September, the US mission in Benghazi – a consulate rather than an embassy, because it was not in the capital – was attacked and burned, in a raid that killed US ambassador Chris Stevens and three other Americans.
It was initially treated as an attack by an angry mob who had been incensed by an Islamophobic film, but later deemed a terror attack. A militia leader was convicted earlier this year in a US court for his role in the violence.
The attack came to dog Hillary Clinton’s bid for the presidency, because she was secretary of state at the time of the deaths. She was cleared by a fiercely partisan congressional panel after a $7m investigation but critics, including Donald Trump, continued to attack her both for perceived failings and for alleged cover-ups.
The raid diminished western appetite for intervention in the region, where the hope of democracy and justice unleashed by the Arab spring was being clouded by violence, from Syria to Libya.
Stevens arrived in Syria the year after the revolution that deposed Muammar Gaddafi, but the country was already riven by violence and extremely unstable.
In the attack, militia stormed a lightly protected compound where Stevens was staying. Although he retreated to a safe room with fellow Americans, he was killed by smoke inhalation from a blaze that had been set outside. The smoke also killed a fellow diplomat, Sean Smith, and a mortar attack on a CIA annexe later that evening killed two officers.