Britain and America, at times they seem like the best of friends, at others they are barely speaking. Click on the graph above to find out more about the highs and lows of the two countries' special relationship.
1773 Boston Tea Party
Dissent over taxation was already brewing in Britain's colonies in America when Parliament passed the Tea Act in 1773.
It favoured the almost bankrupt English East India Company over local traders and the colonial public reacted by boycotting tea.
When three East India ships docked in Boston, 50 activists dressed as Mohawk Indians got on board and dumped the cargo in the harbour.
1775-81 War of Independence
The British backlash to the tea party and other issues culminated in the War of Independence which the British lost in a decisive defeat at Yorktown.
The two sides were back at war in 1812 however and matters were hardly soothed by the British setting fire to the White House and the Capitol.
It was during this war that Francis Scott Key was inspired to write his poem The Star Spangled Banner which was to become the American national anthem.
1861-65 American Civil War
Britain was officially neutral during the Civil War but British ships aided the Confederate side by running guns and supplies through the Union blockade.
This resulted in a diplomatic incident when British mail ship the Trent, carrying two Confederate commissioners was halted by a Union ship and the Confederate diplomats were arrested.
This broke naval law and almost led to war between Britain and the Union but after negotiations - including an intervention by Prince Albert - the threat was averted.
1914-1918 World War I
The US stayed out of World War I for the first half of the war but entered in 1917 after German U boats grew increasingly aggressive in the Atlantic, sinking several American ships.
The arrival of US troops in Europe in 1918 was a huge morale boost for the Allies but the Americans also suffered high casualty rates.
1929 Wall Street Crash
In the inter-war years America followed a policy of isolationism, seeking to distance herself from European affairs.
The Wall Street Crash of 1929 however had a drastic effect on the fragile European economies and is believed to be the origin of the phrase: "When America sneezes Europe catches the cold"
Churchill and Roosevelt
The term "special relationship" was first coined to describe the strong ties forged between US President Franklin D Roosevelt and Winston Churchill during World War II.
As well as discussing military and diplomatic strategy, the two struck up a deep friendship and exchanged thousands of messages and phone calls.
Once again American troops made a crucial difference to the outcome of war - but there was more than a little rancour among the British public that they did not enter the fray until 1941.
1965-73 Vietnam War
Prior to the death of John F. Kennedy in 1963, UK-US relations were again on a high - the young president got on like a house on fire with elder statesman Harold Macmillan and consulted him over the Cuban missile crisis and other cold war issues.
But all was not so rosy between the two nations in the era of Harold Wilson and Lyndon B Johnson. Wilson resisted sending British troops to Vietnam and the special relationship cooled for 15 years.
Thatcher and Reagan
The special relationship reached its high water mark in the alliance of Margaret Thatcher and Ronald Reagan who found their ideological soulmate in each other (so much so that satirical puppet series Spitting Image once portrayed them locked in a passionate embrace).
The personal warmth between them saw them through the inevitable conflicts of interest - Reagan admired Maggie as "One hell of a tough lady" when she twisted his arm over the Falklands.
However the UK baulked when the US invaded the Commonwealth island of Grenada without warning.
It was Thatcher who first accepted Mikhail Gorbachev as "a man I can do business with" and between them, the three leaders forged a new era in international relations.
1991 Gulf War
This period was largely successful for the alliance, although Thatcher did have to tell George Bush senior: "Don't go wobbly on me," the day after Saddam Hussein invaded Kuwait.
However the relationship waned once John Major and Bill Clinton came into office. There were suspicions that the Tories had helped Clinton's Oxford files get into the hands of his political opponents.
Blair and Clinton
Like Thatcher and Reagan, Tony Blair and Bill Clinton clicked on a personal level as well as political.
Members of Clinton's campaign team helped Blair in the run up to the 1997 UK general election and later the pair collaborated on Northern Ireland, the Balkans and Kosovo. Blair was also a friend to Clinton during the time of the Monica Lewinsky scandal.
After the strength of Blair's relationship with Clinton, many thought the election of George W Bush would mark a downturn in Anglo-US relations.
But Blair refused to bad-mouth Bush, saying that people should not underestimate his intelligence.
After September 11th Britain was quick to stand shoulder to shoulder with the US and this stance has continued with Blair throwing his weight fully behind the Iraq war.
"We should remain the closest ally of the US... not because they are powerful, but because we share their values," he said.