Sen. Daniel K. Inouye was sworn in on June 28 as president pro-tempore of the Senate, following the death of Sen. Robert C. Byrd of West Virginia. Inouye becomes third in line to succeed the president. Vice President Joe Biden and Speaker of the House Nancy Pelosi are ahead of Inouye.

Inouye described Byrd in a statement as his “mentor. Over the years he provided me countless opportunities and tasked me with positions of critical national oversight while guiding my actions with the temperance he learned as the longest serving senator in history.”

First elected to the U.S. Senate in 1962, Inouye, 85, is the most senior member of the U.S. Senate.

He is also the chairman of the Senate Committee on Appropriations.

A Nisei, Inouye is a Congressional Medal of Honor recipient, and a veteran of World War II.