Jimmy Carter
The former first lady was the only spouse who did not attend along with the five living presidents.
A two-second clip of the moment between the former presidents has been viewed tens of millions of times.
"We have an obligation to give hate no safe harbour," the president asserted with Donald Trump in the audience.
The president-elect sat in the row directly ahead of Mike Pence, who was once the target of a violent mob bent on keeping Trump in power.
"The Democrats are all 'giddy,'" the president-elect complained.
The prime minister praised the 39th president's "lifelong dedication to peace".
Carter's death sparked a rare, likely scenario that hasn't occurred in over half a century.
The president declared that he can't imagine Carter looking the other way when someone "needed something."
The Georgia Democrat was the longest-lived ex-president, serving one term in the White House before dedicating his time to humanitarian work.
Boris Johnson channels Jim Callaghan as the UK faces economic meltdown.