Daniel Tarullo will resign from the Federal Reserve Board of Governors effective in April, he said in a letter to the president on Friday.

President Barack Obama appointed Tarullo to the board in 2009, filling an unexpired term ending Jan. 31, 2022. With Tarullo’s departure, President Donald Trump will now have three vacancies to fill on the board, which totals seven when all of those seats are filled.

During his tenure at the Fed, Tarullo earned a reputation as a strong regulator who was dovish on monetary policy. Tarullo was strict about enforcing reforms under the Dodd-Frank Act and carrying out stress tests of the very largest banks in the United States. While at the Fed, Tarullo served as chairman of the board’s Committee on Supervision and Regulation and as chairman of the Financial Stability Board’s Standing Committee on Supervisory and Regulatory Cooperation.

“Dan led the Fed’s work to craft a new framework for ensuring the safety and soundness of our financial system following the financial crisis and made invaluable contributions across the entire range of the Fed’s responsibilities,” Chair Janet L. Yellen said in a statement. “My colleagues and I will truly miss his deep expertise, impeccable judgment, wise insight, and strategic counsel.”

Before he joined the Fed’s Board of Governors, Tarullo was a professor of law at Georgetown University Law Center, where he taught courses in international financial regulation, international law and banking law. Prior to that, he held several senior positions in the Clinton administration and earlier, he served on the staff of the late Senator Edward M. Kennedy.