The United States on Wednesday announced normalisation of relations with Cuba, including re-establishing diplomatic ties ending the last of the remaining Cold War hostilities.
The announcement came with the release of an American Cuba had held for five years, and a swap of intelligence assets held by the two countries brokered and blessed by the Vatican.
President Barack Obama and President Raul Castro spoke on phone for 45 minutes on Tuesday, a senior US official said, "in the first such conversation since the Cuban revolution".
US and Cuba have not had diplomatic ties since 1961, the year before the 1962 missile crisis that brought the world to the edge of a nuclear war involving then superpower, USSR.
With the normalisation of ties, US and Cuba will open - re-open - embassies, allow significantly more travel and trade, and let touring Americans bring back Cuban cigars.
The United States initiated normalisation talks in the spring of 2013 as, a senior administration official said, the hostilities were clearly well past their "expiration date".
The first face-to-face meeting between US and Cuban officials took place in June 2013. Canada hosted it but did not participate in it, as it would a few more subsequently.
Pope Francis was pulled in earlier this year at a meeting at Vatic with President Obama. US ties with Cuba figured prominently in the discussions, said a senior administration official.
The Vatican would not only be the host but a participant. The swap of prisoners - one American intelligence officer for three Cuban - was finalised at the Vatican in November.
Alan Gross, 65, was not included in the swap, as US insisted he was not an intelligence asset - but a USAID contractor. Cuba released him on humanitarian grounds, officials said.
Gross was captured setting up an illegal internet network through satellite in Cuba in 2009. Havana charged him with espionage, and refused to release him despite repeated calls.
Officials denied USAID administrator Raj Shah's exit, announced just before the deal with Cuba became public, had anything to do normalization of ties with Havana.
Cuba is not a fan of USAID's efforts to spread democracy around the world, which Shah did as a part of his work requirement. But his departure was not linked.