US President Barack Obama and Cuban President Raul Castro have greeted each other at a summit in Panama - a symbolically-charged gesture, as the pair seek to restore ties between their countries.
For Barack Obama this will surely be amongst the highlights of his presidential legacy.
He's in Panama for a gathering of leaders from across the Americas - but it's a meeting that has taken place on the sidelines of the summit which will attract the headlines.
That meeting has taken place with Raul Castro.
Touching down in Panama City, even getting invited is a first for the Cuban President - after half a century in exile for his communist country.
The two men had spoken by phone - hours before they were due to meet.
It was only the second conversation between the leaders of the US and Cuba in 50 years.
Four months ago Mr Castro and Mr Obama simultaneously announced an ending of hostilities.
President Obama said starkly: "Fifty years of isolation hasn't worked."
It was quite a statement. But words come easy to the eloquent president. Now it's time to show Cuba has come in from the cold.
The handshake between the two leaders is symbolic proof of that.
It isn't technically the first time they have shaken hands.
There is a grainy image of them fleetingly meeting at the Memorial Service for Nelson Mandela in South Africa in 2013.
But this time the handshake is supposed to mean more because it comes after the leaders' December declaration of a new beginning.
Speaking in Panama, President Obama said: "As we move towards the process of normalisation, we'll have our differences government to government with Cuba on many issues, just as we differ at times with other nations within the Americas, just like we differ with our closest allies, there is nothing wrong with that.
"But I am here to say when we do speak out we're going to do so, because the United States of America does believe, and will always stand for, a certain set of universal values."
And that means probably taking Cuba off America's designated list of state sponsors of terrorism. Something which infuriates Cuba.
The rapprochement will also open the door towards loans and aid for Cuba after decades of a crippling trade embargo. And that is a move worth its weight in gold.
Fidel Castro came to power in 1959 after overthrowing the US-backed dictator Fulgencio Batista.
For half a century, the leader of the first communist country in the western hemisphere was a thorn in America's side.
In 2006 after abdominal surgery he started the transfer of power to his brother Raul who took the landmark step in 2014 of appearing with the US President.
Removing Cuba from the terror list will be a major step if ties really are to be rebuilt between the US and Cuba.
An historic moment after 50 years which has seen America try to isolate Cuba and finally acknowledge it as a neighbour.
