US President Donald Trump has announced that the US is recognising Jerusalem as the capital of Israel and will relocate its embassy from Tel Aviv to Jerusalem.
This reverses decades of US foreign policy - and international policy - not to recognise Jerusalem as the capital to avoid influencing the ongoing Israeli-Palestine peace process.
The status of Jerusalem has long been a sticking point in the decades of peace talks of efforts to find a two state solution. Both Israel and Palestine lay claim to the city.
The international community has been in agreement - until now - that a ruling one way or another would inappropriately influence the peace process.
Israel believes Jerusalem to be its "eternal and indivisible" capital city. Palestine wants the capital of any independent Palestinian state to be located in the eastern part of the city.
Israel captured that part of Jerusalem in the 1967 Middle East war and annexed it in a move that was never recognised internationally.
No other country has its embassy in Jerusalem. The issue is so contentious, that Mr Trump's decision threatens regional stability, and many US allies have distanced themselves from the move.
A Palestinian envoy described the US President's endorsement of Jerusalem as Israeli capital as equating to a declaration of war on the Middle East, while Pope Francis weighed in to call for the "status quo" to be respected.
The international community does not recognise Israeli control over Jerusalem, and it is home to holy sites in the Muslim, Christian and Jewish faiths.
The endorsement has been interpreted as an acceptance that Jerusalem belongs exclusively to Israel.
Although Mr Trump has directed the State Department to begin looking for a suitable site for an embassy in Jerusalem, it will be years before the move is complete.
The process to build a secure compound and relocate diplomatic operations from Tel Aviv will be long and complex. An administration official estimated it would take at least three to four years.
The US President promised to move the embassy to Jerusalem on his election campaign trail, and a White House official said he was doing so to reflect the reality of the situation that Jerusalem is the administrative capital of Israel - the Parliament, the Prime Minister and the Supreme Court are all located there.