WASHINGTON (AP) — White House communications director Hope Hicks, one of President Donald Trump’s most trusted and longest-serving aides, abruptly announced her resignation, leaving a void around a president who values loyalty and affirmation.

The departure of Hicks, who worked as a one-woman communications shop during his campaign, came as a surprise Wednesday to most in the White House — and cast a pall over the West Wing at a trying time for the president. It leaves Trump increasingly without support of the familiar aides who surrounded him during his campaign, and marks the latest in a string of high-level departures in the administration’s second year.

Hicks, 29, had a seemingly untouchable role in the West Wing, often viewed more as a surrogate daughter than a staffer. Perhaps most importantly, she served as Trump’s glamorous shield and validator, always ready to provide “Mr. Trump” with a smiling dose of positive reinforcement, and controlling reporters’ access. She was the fourth person to occupy the position since the president was sworn in, as the Trump White House has set modern records for staff turnover.

In a statement, Trump praised Hicks for her work over the last three years, saying he “will miss having her by my side.” Hicks informed Trump of her decision Wednesday, a White House official said.

Hicks, who occupied the desk closest to the Oval Office in the West Wing, has been a central participant in or witness to nearly every milestone and controversy of the Trump campaign and White House. She began her White House tenure as director of strategic communications — a title that only partly captured her more expansive role as the president’s gatekeeper to the press.

The news comes a day after Hicks was interviewed for nine hours by the House panel investigating Russia interference in the 2016 election and contact between Trump’s campaign and Russia.

Hicks acknowledged to the House intelligence panel Tuesday that she has occasionally told “white lies” for Trump, according to a person familiar with the testimony.

But she said she had not lied about anything relevant to the Russia investigation. She has also been interviewed by special counsel Robert Mueller’s team about her role in crafting a statement about Donald Trump Jr.’s 2016 meeting with Russians, as Mueller’s expansive probe of Russian interference in the 2016 election and potential misdeeds committed by those in the president’s orbit moves ever closer to the Oval Office.