Big news in the energy world yesterday: Big Oil will get its first female CEO.

Meg O’Neill will become the new CEO of BP, effective April 1, Fortune‘s energy editor Jordan Blum reports. She had been the CEO of Woodside Energy for four years and was a longtime vet of Exxon Mobil, where she became an executive adviser to Rex Tillerson.

BP, with $195 billion in annual revenue, ranks No. 33 on the Global 500 and No. 5 on the Fortune 500 Europe. It’s headquartered in London.

As O’Neill steps into the massive role, she’s facing a bit of a glass cliff scenario. O’Neill is the energy producer’s fourth CEO in six years. CEOs have been in and out for a variety of reasons; one, Bernard Looney, left after failing to disclose a relationship with a colleague. Current CEO Murray Auchincloss stepped in after that incident.

On the business side, Looney had tried to transform BP into a green energy giant, with mixed results. As one analyst put it: the company “rather kind of drank a bit too much Kool Aid on the whole energy transition and neglected its core businesses.”