President Donald Trump announced Sunday morning that Islamic State leader Abu Bakr al-Baghdadi was killed in a special operations raid in northwestern Syria over the weekend.

"Last night was a great night for the United States and for the world. A brutal killer, one who has caused so much hardship and death has violently been eliminated," Trump said from the White House.

The president had teased a major announcement Saturday night.

Here's what we know about the ISIS leader:

Al-Baghdadi led ISIS for 5 years

Al-Baghdadi, the highest-ranking terrorist to be killed or captured since Osama bin Laden's death in 2011, headed the terrorist organization ISIS for the past five years. ISIS has become notorious for its brutal killings and beheadings.

Until his death, al-Baghdadi remained one of the few ISIS leaders still at large as his "caliphate" shrank and supporters were imprisoned.

Concerns that captured members of ISIS would escape heightened after Trump announced this month that U.S. forces would pull out of northern Syria, effectively clearing the way for a military invasion by Turkey on Kurdish forces who had fought ISIS alongside the United States. An unknown number of ISIS fighters were released, and the U.S. and Turkey negotiated a cease-fire deal.

He was one of the most wanted men in the world

Al-Baghdadi had a $25 million U.S. bounty on his head. There had been multiple previous reports of the leader's death.

"Capturing or killing Baghdadi has been the top national security priority of my administration," Trump said Sunday.

U.S. special operations forces, with the assistance of the CIA, located al-Baghdadi late Saturday. Trump said he was killed while running into a dead-end tunnel.

Both the Kurds and the Turks said they provided assistance to the U.S. raid.

More:President Trump says ISIS leader Abu Bakr al-Baghdadi is dead after U.S.-led raid in Syria

He urged terrorist attacks on the United States

Al-Baghdadi urged his followers to strike Western countries, including the United States.

He was shown in a video for the first time since 2014 earlier this year when he praised attackers who killed more than 250 people, including four Americans, in bombings in Sri Lanka over Easter Sunday. He also released an audio recording last month calling on supporters to help free ISIS detainees.

Al-Baghdadi helped lead a shift in ISIS operations toward acts of violence that would be hard for governments and law enforcement to prevent, as opposed to more large-scale attacks.

'He died like a dog'

A U.S. raid ended with al-Baghdadi cornered in a dead-end tunnel alongside three of his children, Trump said. Al-Baghdadi and those children died when he detonated a vest he was wearing. Two women were also found dead.

"He died after running into a dead-end tunnel, whimpering and crying and screaming all the way," Trump said. He said Al-Baghdadi was chased by U.S. military dogs.

The president said DNA testing was done at the site of the blast, and body parts were retrieved by U.S. forces. He said results were "totally positive" in proving al-Baghdadi's identity.

No U.S. personnel were killed during the raid, Trump said, but a "large number" of al-Baghdadi's companions were killed.

"He died like a dog. He died like a coward," Trump said.

Contributing: David Jackson, Courtney Subramanian, Michael Collins and the Associated Press