Former Senate Majority Leader Howard Baker (R-Tenn.) has died at the age of 88.

Baker served as majority leader from 1981 to 1985, and was later a chief of staff to President Reagan. He also played a memorable role in the Watergate trial, asking "what did the president know and when did he know it?" as the ranking Republican on the investigative committee. 

“It is with great sadness that I announce the passing of one of the Senate’s most towering figures, Sen. Howard Baker," Senate Minority Leader Mitch McConnellMitch McConnellTop Dem: ‘Ironic’ McCain could back bill that would put people with illnesses at risk Bill Maher on McCain: Someone in a health crisis should see how wrong repealing ObamaCare would be Congress must repeal the debt limit so no party can take it hostage MORE (R-Ky.) said on the Senate floor, announcing the death. "The Senate sends its sincere condolences to the family of Sen. Baker.” 

Baker was called the “Great Conciliator” because of his ability to strike compromises. He served as U.S. ambassador to Japan under former President George W. Bush.

“Sen. Baker was a true path breaker. He served as Tennessee’s first popularly elected Republican senator since reconstruction. He served as America’s first Republican majority leader since the time of Eisenhower,” McConnell said.

President Obama said it was Baker's "ability to broker compromise and his unofficial role as the “Great Conciliator” that won him admirers across party lines, over multiple generations, and beyond the state he called home."

"Over an 18-year Senate career, Howard fought for the people of Tennessee and helped lead America through difficult times," the president said in a statement, extending his thoughts and prayers to the Baker family.

Senate Majority Leader Harry ReidHarry ReidConservative Senate candidate calls on GOP to end filibuster Ex-Reid aide: McConnell's 'original sin' was casting ObamaCare as 'partisan, socialist takeover' GOP faces growing demographic nightmare in West MORE (D-Nev.) also mourned Baker's passing.

"The Senate has lost a member of its family," Reid said. "My sympathy goes to Senator Baker, his family, his friends, especially the two senators from Tennessee, who I'm sure are heartbroken."

Before becoming majority leader, Baker ran for president in the 1980 Republican primary. He dropped out due to poor performances in the early primary states. 

"Senator Baker was one of the best leaders the Senate has ever had. We have lost a true statesman," said Sen. Patrick Leahy (D-Vt.), the Senate president pro tempore.

—Alexander Bolton contributed

This story was updated at 6:26 p.m.