The New York state education commissioner unexpectedly announced she is retiring.

New York State Education Commissioner MaryEllen Elia submitted her resignation letter to the Board of Regents Monday. She says her last day will be Aug. 31.

Elia was appointed to the position in July 2015. She succeeded the troubled tenure of former commissioner John King, who sparred with education leaders over the tougher standards under Common Core.

Elia is the state's first woman education commissioner.

She calmed the waters with the teachers union, parents and students over the testing. Ultimately, the state Education Department and the Board of Regents scaled back the testing and no longer ties standardized tests to student or teacher performance.

"She helped us get through the whole Common Core mess that started before her," said Regents member Roger Tilles.

Tilles says while the timing of her resignation is a surprise, he expected Elia would step down at some point. He says Elia and board members have had several disagreements during the past year.

"There were some differences in terms of redoing and reevaluating the whole special education area and eliminating some of the parent advisory groups, which on Long Island are very strong. And she did some of these things without consulting or even mentioning it to the Regents and that, some of us, found to be problematic," Tilles said.

During her four-year tenure, Elia also oversaw efforts to turn around two troubled Long Island school districts -- Hempstead and Wyandanch. Both districts could soon be under the watch of state fiscal and academic monitors.

Elia did not offer an explanation for stepping down. The Board of Regents is expected to name an interim education commissioner as early as this week.

Tilles says a nationwide search will be conducted for a new commissioner. He says that search could take six to nine months.