US Attorney General Jeff Sessions submitted his resignation letter to White House Chief of Staff John Kelly Wednesday at the request of President Donald Trump.

In the letter, Sessions touted the record numbers of “violent offenders and firearm defendants” the Justice Department prosecuted while under his watch.

Trump announced via twitter that Matthew Whitaker, Chief of Staff to Sessions, would take over as acting attorney general. Whitaker has the ability to take over managing the the Russia investigation, and special counsel Robert Mueller, from Deputy Attorney General Rod Rosenstein.

Sessions was once one of Trump’s most vocal and earliest supporters during the 2016 campaign. However, his resignation has been expected for weeks leading up to the mid-term election. In the past, Trump has described Sessions in interviews, tweets and press conferences as “beleaguered” and described the Justice Department under Sessions as “A Total Joke!”

In September, Trump indicated his fractured relationship with Sessions by stating “I don’t have an attorney general. It’s very sad,” in an interview with Hill.TV.

The complaints only ramped up in recent weeks, with Trump describing Sessions as “disgraceful” for asking the Justice Department’s inspector general, instead of DOJ lawyers, to review possible FISA abuses related to the monitoring of a former Trump campaign aide. There has been no word on what action, if any, Acting Attorney General Matthew Whitaker will take regarding the Russia investigation.