South Korea's Constitutional Court reinstated impeached President Roh Moo-hyun (search) in a historic ruling Friday, rejecting a parliamentary move to oust the embattled leader.

The ruling, broadcast live on national television, took 30 minutes and covered three main charges against Roh — illegal campaigning, incompetence and economic mismanagement.

The high court cleared the leader of the charge of economic mismanagement and incompetence for failing to rein in corruption among several former aides. The court found Roh had violated election laws but said the infraction was not serious enough to warrant impeachment.

"The court found the charges of illegal electioneering was not serious or grave enough to justify the unseating of the president," court President Yun Young-chul (search) said.

Roh resumes his executive duties immediately.

South Korea entered uncharted territory in March when Roh became the first president impeached by its legislature, just one year into his five-year tenure.

The move humiliated the fledgling leader, rattled markets, agitated neighboring North Korea and drove tens of thousands of people into the streets to protest against the opposition-backed ouster attempt.

Prime Minister Goh Kun (search) had assumed Roh's executive duties while the Constitutional Court reviews the case.

Expectations had run high that the nine-justice Constitutional Court would strike down the National Assembly's March 12 impeachment vote. The court held seven hearings on the case.

Roh's reinstatement gives the progressive 57-year-old president a fresh mandate for his policies of closer ties with North Korea (search) and economic reform.

If the court had upheld Roh's removal, it could have triggered another bout of political instability, setting the stage for a new presidential election within 60 days. Roh would have been barred from running.

The two main opposition parties impeached Roh on charges of minor electioneering violations and incompetence, for failing to rein in corrupt aides. Polls showed, however, that seven in 10 South Koreans opposed the move, calling the grounds flimsy and politically motivated.

The National Police Agency tripled the number of officers dispatched around the court house to 200. Dozens of police buses ringed the court house, which was closed to tourist, while officers patrolled the area.

A group of Roh backers rallied nearby with pickets reading: "Our country without a president is embarrassing." A handful of impeachment supporters had also gathered.

"We are calmly, yet tensely, awaiting the result," presidential spokesman Yoon Tae-young said.

The presidential Blue House Web site carried a photograph of Roh smiling, looking confident and thrusting a clenched fist toward supporters. He was quoted as saying the impeachment was "not just a painful and wasteful process but rather the growing pain for new advancement."

Public outrage against the impeachment vote soon translated into a political windfall for Roh. The small, liberal-leaning Uri Party (search) that backs him tripled its National Assembly seats in a nationwide April 15 election to take a slim majority and break the conservatives' four-decade grip on parliament.

"We expect a wise Constitutional Court ruling that honors the will of the people," the Uri Party said in a statement Thursday, referring to its strong showing in the polls.

Roh's reinstatement is a crowning victory for the liberal-leaning legislature. Though not an Uri member, Roh champions many of its policies and has said he'll join.

The main opposition Grand National Party, which helped spearhead the impeachment only to be punished in the ballot box backlash, was rocked Wednesday when a key member urged the party to "kneel and apologize to the people 100 times" if the court rules in favor of Roh.