Donald Trump heralded a new era of protectionism and isolationism as he became the 45th president of the United States.
Mr Trump's inauguration speech on Capitol Hill was noteworthy for its lack of any magnanimity in the wake of a hugely divisive election.
In his address, the billionaire businessman introduced his policy of "America First".
He conjured up an image of "American carnage", depicting cities afflicted by crime, a political class out of touch with ordinary people and rusted factories with jobs lost overseas.
"From this day forward a new vision will govern our land. From this day forward it's going to be only America first. America first," he said.
America first extended to foreign policy too, as he vowed every decision on trade, taxes, immigration, and on foreign affairs will be made "to benefit American workers and American families".
The new US president pledged to "eradicate" radical Islamic terrorism by reinforcing old alliances and forming new ones.
His address contained populist promises echoed across his campaign. "We are not transferring power from one administration to another, nor from one party to another, but we are transferring power from Washington DC and giving it back to you, the people," he said.