Republican Alabama Sen. Richard Shelby will retire at the end of his current Senate term, the fourth sitting Republican senator to announce that he will not seek reelection in 2022.

“For everything, there is a season,” Shelby said in a statement on Monday. “I am grateful to the people of Alabama who have put their trust in me for more than forty years. I have been fortunate to serve in the U.S. Senate longer than any other Alabamian.”