Barack Obama has delivered his final address as President of the United States. Here's a look at some of his most memorable speeches, which captured hearts and minds around the world.
2004: Democratic National Convention
What: It was the moment that thrust him into the national spotlight. A relatively-unknown Senate candidate, Barack Hussein Obama, took to the stage for the keynote address.
Where: The Democratic National Convention in Boston.
Key point: His speech shared the story of his heritage, of his father who was born in a small village in Kenya and his mother who was born on the other side of the world in Kansas.
I stand here knowing that my story is part of the larger American story, that I owe a debt to all of those who came before me, and that in no other country on Earth is my story even possible."
2008: A More Perfect Union
What: Mr Obama addressed race and religion in this campaign-defining speech, saving his derailing presidential bid.
Where: The National Constitution Centre in Philadelphia, Pennsylvania.
Key point: Lecturer in US politics and foreign policy, Gorana Grgic, from the University of Sydney's United States Studies Centre, said this was a defining moment for the then presidential hopeful.
It followed controversy over old racially inflammatory remarks from his former pastor, Jeremiah Wright, which had resurfaced during the presidential campaign.
"That was very much a speech that put in the forefront his mixed-race background and basically put him in this ... unique position to speak bluntly to both black and white Americans," Dr Grgic said.
During the speech Mr Obama said he could "no more disown him than I can disown the black community".
I can no more disown him than I can my white grandmother — a woman who helped raise me ... who once confessed her fear of black men who passed by her on the street. These people are a part of me. And they are a part of America, this country that I love."
2008: Election victory
What: The President-elect fronted a crowd of thousands after receiving a concession call by Republican candidate John McCain for the 2008 US election.
Where: He gave his election victory speech in Chicago, where he delivered the final speech of his presidency.
Key point: This was the moment Mr Obama's supporters had been waiting for after a long campaign, and there was more than one 'yes we can'.
The road ahead will be long. Our climb will be steep. We may not get there in one year or even in one term. But, America, I have never been more hopeful than I am tonight that we will get there."
2009: Nobel Peace Prize acceptance
What: The President was awarded "for his extraordinary efforts to strengthen international diplomacy and cooperation between peoples".
Where: Oslo City Hall.
Key point: Dr Grgic said this was another key moment, but one which caused some criticism.
"He was saying he was not against all wars he was just against stupid wars and I think that defined a lot about his foreign policy doctrine," Dr Grgic said.
Mr Obama said:
We must begin by acknowledging the hard truth: We will not eradicate violent conflict in our lifetimes. There will be times when nations — acting individually or in concert — will find the use of force not only necessary but morally justified ..."
2011: Tuscon memorial in Arizona
What: The President delivered a speech following the January 8 shooting of US representative Gabrielle Giffords and 18 other people during a constituent meeting in a supermarket parking lot. While she survived, six others died.
Where: The University of Arizona.
Key point: Mr Obama delivered a speech which told the story of each of the victims.
There is nothing I can say that will fill the sudden hole torn in your hearts. But know this: The hopes of a nation are here tonight."
2015: 50th anniversary of Selma marches
What: The 50th anniversary commemoration of the Selma to Montgomery marches.
Where: Selma, Alabama.
Key point: ANU Marketing lecturer Andrew Hughes said it was one of the President's best.
"One of his best speeches he's ever delivered is the Selma speech which he delivered at the 50th anniversary of the walk across the bridge in Selma in the United States, on the Civil Rights Movement," he said.
"The setting there, and the anniversary date, all played into the context and his delivery of the speech itself, to make it probably one of his best ever."
Mr Obama said:
For everywhere in this country, there are first steps to be taken, and new ground to cover, and bridges to be crossed. And it is you, the young and fearless at heart, the most diverse and educated generation in our history, who the nation is waiting to follow."
2015: Charleston eulogy
What: The President delivered a eulogy for the pastor and eight parishioners killed by gunman Dylann Roof.
Where: College of Charleston, Charleston, South Carolina.
Key point: He gave a passionate eulogy and even sang the opening line of Amazing Grace on live television.
It is up to us now to make the most of [God's grace], to receive it with gratitude, and to prove ourselves worthy of this gift."
2016: Rutgers University commencement
What: He spoke at the 250th anniversary of the State University of New Jersey to the graduating class.
Where: Brunswick, New Jersey.
Key point: He noted the negativity of the world, and the positive influence the next generation could have. There was even time for a dig at then Republican-presidential nominee Donald Trump.
In politics and in life, ignorance is not a virtue. It's not cool to not know what you're talking about."