Sophie Dagenais, a former corporate lawyer who has served as Mayor Stephanie Rawlings-Blake's chief of staff for the past year, will resign effective March 21.

"It was always our plan, the mayor's and mine, that I come here for a finite period time," Dagenais said in an interview. "My work is done."

Dagenais, who worked for the Ballard Spahr law firm before joining Rawlings-Blake's administration, said she had not yet lined up her next position. She said she had always planned to leave after a year, although city officials left out that detail when they trumpeted her arrival last year.

Dagenais said she was leaving to allow a permanent chief of staff to be chosen.

Prior to joining the Rawlings-Blake administration, Dagenais had been part of a development team that crafted a proposal to build a new arena. That plan was later shelved and city officials are currently contemplating building a combined arena and convention center.

Dagenais was a low-key presence in the Rawlings-Blake administration. In one of her first public appearance last year, council members vented about a lack of transparency Rawlings-Blake's budget plans.

Former deputy chief of staff Kim Washington, who served as chief of staff when Rawlings-Blake was City Council president, has had a more prominent role in the administration, leading negotiations with council members, business leaders and union heads.