It was believed Donald Trump would start firing some members of his administration after the election and now it has started. The first person to go is Defense Secretary Mark Esper. Trump made the announcement on Twitter.

Just last week there were reports that Esper already had prepared a letter of resignation. Esper has been odds at the president since earlier this year. That’s when, as CNBC writes, “In an extraordinary break with Trump, Esper told reporters in June that he did not support the invoking the Insurrection Act, a law from 1807 that would allow Trump to deploy active-duty U.S. troops to respond to civil unrest stemming from protests against police brutality across the country.”

Miller will be Trump’s fifth Defense Secretary.