WASHINGTON: John Christopher Stevens, the U.S. ambassador to Libya killed in the Libyan city Benghazi, was deeply involved in the transition of the North African state and had been U.S. envoy to the rebels who overthrew ruler Moammar Gadhafi last year.

Stevens, the 52-year-old ambassador to Libya since May, is the first U.S. ambassador to be killed in an attack since 1979. He was hailed Wednesday as a skilled and fearless diplomat who had been among the State Department’s rising stars.

“They just killed the best of the next generation in the inner sanctum of the foreign service,” said a retired senior U.S. diplomat who knew Stevens, describing him as a decent, trustworthy and lighthearted man who made friends easily.

The California-born veteran diplomat, an Arabic and French speaker, served as deputy chief of mission in Tripoli between 2007 and 2009, in the waning years of Gadhafi’s mercurial and brutal rule in the oil-rich country.

As the country dissolved into civil war, he was appointed the U.S. envoy to the Transitional National Council, which was coordinating the revolt against Gadhafi, and he returned aboard a Greek cargo freighter that docked in Benghazi in April 2011.

In an email sent to family and friends this summer, Stevens said he was hopeful about the future of Libya.

“The whole atmosphere has changed for the better,” Stevens wrote, according to the International Herald Tribune. “People smile more and are much more open with foreigners. Americans, French, and British are enjoying unusual popularity. Let’s hope it lasts!”

President Barack Obama, who vowed to bring the killers to justice, stressed Stevens’ deep ties to Libya and his commitment to helping Libyans build a nascent democracy out of the chaos of war.

“It is especially tragic that Chris Stevens died in Benghazi because it is a city that he helped save,” Obama said Wednesday. Benghazi had been the cradle of the anti-Gadhafi revolt.

Stevens graduated from the University of California at Berkeley in 1982, taught English as a Peace Corps volunteer in Morocco, where “Stevens fell in love with the Middle East,” Clinton said. He earned a law degree in 1989.

At age 31, Stevens joined the foreign service in 1991 and had postings in Cairo, Damascus, Riyadh and occupied Jerusalem, before working in Libya.

Having spent a career operating in dangerous places, Stevens chafed at the limitations required by security, foreign correspondents who knew him said. As a young political officer, Stevens made a point to visit the volatile West Bank. Recently, he went for daily runs in the Libyan countryside.

Stevens’ return to Benghazi came when the rebel stronghold provided uncertain footing for a diplomatic mission, with its staff forced to spend their first night aboard a ship and later removed from their first home after a car bombing, according to an account in a State Department magazine.

With Gadhafi’s fall and the return of an American Embassy to Tripoli, Stevens recently invited guests for the opening of a consular section in Tripoli to provide visas. It would open a door to America, Stevens said.

“Relationships between governments are important,” Stevens said, according to a transcript of his remarks on Aug. 26, “but relationships between people are the real foundation of mutual understanding.”