(CNN) -- Chris Stevens knew what he was getting into.
He knew, longtime friend Daniel Seidemann said, that Libya was a place of great promise, but also one of great peril.
"When he went to Libya, he had no illusions about where he was going," Seidemann said. "He has probably done more than anybody on the planet to help the Libyan people, and he know going in that this was not going to protect him."
U.S. Ambassador J. Christopher Stevens died Tuesday in an assault on the American Consulate in Benghazi, the very city where he had arrived aboard a cargo ship in the spring of 2011 to help build ties between the upstart rebellion and the rebels.
"He risked his life to stop a tyrant, then gave his life trying to help build a better Libya," U.S. Secretary of State Hillary Clinton said Wednesday.
"The world needs more Chris Stevenses," Clinton said.
Stevens graduated from the University of California, Berkeley, in 1982, then took a pause in his studies to join the Peace Corps, according to his State Department biography.
"Growing up in California, I didn't know much about the Arab world," he said in a State Department video prepared to introduce him to the Libyan people after his appointment as ambassador in May.
"I worked as an English teacher in a town in the High Atlas Mountains in Morocco for two years, and quickly grew to love this part of the world," he said.
After returning to the United States, he attended the University of California's Hastings College of Law, graduating in 1989, according to his biography.
He worked as an international trade lawyer in Washington before joining the Foreign Service, the career diplomatic corps, in 1991, according to the State Department biography.
He spent most of his career in the Middle East and North Africa, including postings to Israel, Egypt, Syria and Saudi Arabia, in addition to serving as the deputy chief of the U.S. mission to Libya from 2007 to 2009, during the rule of Moammar Gadhafi, according to the State Department.
"He joined the Foreign Service, learned languages, won friends for America in distant places and made other people's hopes his own," Clinton said.
It was during Stevens' time as the political section chief in Jerusalem that Seidemann got to know the man dubbed "the senator" for his unflappable character and unrelenting empathy.
"He was the best of the best," Seidemann said. "If there's American nobility, he's it."
Stevens' stepfather, Robert Commanday, remembered the diplomat as a "beautifully even-tempered person."
"In the 36 years that I was privileged to be his stepfather, I never saw him lose his temper once," Commanday told CNN's "The Situation Room."
"And he was calm and easy and people loved him not only for that but because he didn't impose his ideas on them and he was interested in the persons he was talking to."
Commanday said his family was "shattered" by the news of his death.
Seidemann, who focuses on Israel-Palestinian relations, got to know Stevens through work, but they quickly grew to be friends.
"He was extremely warm, friendly, open," Seidemann said.
After returning to Washington to work for a time, Stevens went back to Libya to help try to rebuild U.S. relations with Moammar Gadhafi's regime. Then, in 2011, as Libyans began to take up arms against the dictator, Clinton tapped him for another role.
"In the early days of the Libyan revolution, I asked Chris to be our envoy to the rebel opposition," Clinton said. "He arrived on a cargo ship in the port of Benghazi and began building our relationships with Libya's revolutionaries."
"He was seen as a popular, personable and hands-on diplomat among State Department staffers who knew him," said Elise Labott, a CNN foreign affairs reporter who knew Stevens.
"He wasn't a pinstripe diplomat. He wanted to get his hands dirty, dig in," she said.
Commanday conveyed a similar impression, saying Stevens was "very happy" to get the post.
"He wasn't looking for a ... cushy ambassador's spot," he said. "He loved the Libyan people and was passionate about helping."
Stevens was well-regarded among Libyans, said Fouad Ajami, an expert on Islamic politics.
"The sadness of it is that Ambassador Stevens worked long and hard for the liberation of the Libyan people from the tyranny of Moammar Gadhafi," he said.
Stevens frequently spoke of an infectious enthusiasm for the country that made him "the only person, in the eyes of the State Department," for the Libya post, Labott said.
The ambassador understood Libya and its dangers, but also saw great promise, said CNN's Zain Verjee, who also knew Stevens well.
"Chris was passionate about Libya," she said. "He cared about the people and saw hope in its future. He told me he knew the dangers but was committed to democracy and diplomacy above all."