John King (left), the new state education commissioner, meeting with a teacher in February.

John King is New York’s new state education commissioner, after a unanimous vote by the state Board of Regents this morning.

King, the deputy state education commissioner, replaces David Steiner, who announced he was planning to leave at the end of the academic year in April. The announcement was a surprise, but concerns that Steiner might leave the state in the lurch were tampered by the expectation that King, his close partner, would likely succeed Steiner as commissioner.

King and Steiner’s ambitious agenda has included changing the way teachers are prepared and certified, overhauling the state’s standards, curriculum, and assessments, and implementing a slew of other innovations laid out in New York’s winning Race to the Top application.

Part of that plan was an effort to change the way teachers are evaluated. Members of the Regents vote today on whether to approve the plan that state education officials are proposing. Under urging from Governor Cuomo, the plan increases the portion of a teacher’s evaluation that would depend on student test scores to 40%. Any actual teacher evaluation system, though, will have to be bargained in each local district by school officials and local teachers unions.

Regents members are expected to approve the new regulations later today. (You can watch the vote via webcast here.)

King previously served as a managing director at Uncommon Schools, a network of charter schools, and founded the high-performing Roxbury Preparatory Charter School in Boston. He is widely respected inside the community of education activists who support charter schools, but he has a calmer style than hard-charging reformers like Joel Klein, the former city schools chancellor.

And King’s experience as a teacher and principal — in addition to a law degree from Yale, he also holds a Master’s and education leadership degree from Teachers College at Columbia University — mean he speaks about education less as a political effort and more as a teaching and learning enterprise.

In September, King turned down an offer to take on another high-profile education job as superintendent in Newark, New Jersey.

UPDATE: The New York Times story on King’s appointment is up. It includes an interview with him about his background — both of his parents had died of illness by the time he was 12 — and describes him as the “details person” who complemented Steiner’s vision.