For more than a year after taking office, President Donald Trump maintained a relatively stable team, with no major personnel changes. That stability began to unravel in mid-March, when a wave of departures swept through the administration, affecting top officials across the Cabinet, intelligence agencies, and military leadership.

The latest shake-up came Wednesday, when the Pentagon confirmed that Navy Secretary John Phelan would be stepping down.

Here’s a closer look at the key exits shaping Washington this spring.

Kristi Noem

Kristi Noem, the former governor of South Dakota, led the Department of Homeland Security’s aggressive immigration crackdown, a cornerstone of Trump’s campaign agenda.

Her tenure, however, was overshadowed by controversy. Two fatal shootings of American citizens by federal officers in Minneapolis drew national attention. After the second incident, Trump sidelined Noem and dispatched border adviser Tom Homan to manage the situation.

Noem also faced bipartisan criticism in Congress over delays in disaster relief funding. Lawmakers blamed a policy requiring her personal approval for contracts and grants exceeding $100,000.