It's been quite a ride for U.S. Ambassador to China Gary Locke, who announced today he will be leaving the post he assumed in August 2011. Here are five of the moments that made Locke's two-years-and-change in Beijing so topsy-turvy. They're a reminder of both Locke's unusual public stature in China -- he became something of a celebrity for living like a normal person in a country where public officials carry themselves like royalty -- and the tumultuous few years of U.S.-China relations that his tenure spanned.

August 2011: Locke becomes a celebrity in China before even arriving.

While at the Seattle airport waiting for his flight to depart, Locke was photographed by a Chinese businessman while buying a coffee at Starbucks. The businessman posted the photo to Chinese social media, where it generated huge discussion. Chinese Web users were amazed to see a high-powered American official buying his own coffee and carrying his own backpack. The idea that a public official might live like a regular person is one we take for granted in the United States but is extremely rare in China; that sense of disconnect between citizens and officials is highly sensitive. Locke's regular-person lifestyle drew attention to that issue. The blog Shanghaiist summarized the popular Chinese reaction to Locke getting photographed in the coach class of an airplane like this: "Chinese internet users again think the sky is falling after Gary Lock flies coach class, like some kind of poverty-stricken farmer's cattle."

November 2011: Locke visits his ancestral village.

Locke was the first Chinese American to serve as U.S. ambassador to China. So when he visited his family's ancestral village of Jilong, in southern China, it was a big deal. (He'd visited twice before but never in his official capacity.) It was a symbol of the Chinese U.S. diaspora, as well as a reminder of how much success that community has found in the faraway United States. You can't fake soft power like that.

February 2012: The Wang Lijun crisis

When Chongqing police chief fled to the U.S. Consulate in nearby Chengdu and requested asylum, apparently fearing that regional party boss Bo Xilai would have him killed, it set off, first, a U.S.-Chinese near-crisis and then a much larger political crisis within China. The former was resolved quickly and quietly; Locke revealed months later that he had been involved in striking a deal for Wang to leave the consulate peacefully. But Wang's arrest was soon followed by the dramatic fall of Bo, perhaps the moment of greatest political turmoil in China since 1989.

May 2012: Activist Chen Guangcheng shows up at the U.S. Embassy.

Chen, after spending years under house arrest for fighting for extremely basic human rights, escaped his guards and traveled several hundred miles to the U.S. Embassy compound in Beijing, an escape made even more amazing by the fact that he is blind. It set off a profoundly serious crisis in U.S.-China relations -- granting Chen asylum would have been a slap in Beijing's face --  that lasted a couple of weeks. Locke and other U.S. officials negotiated a surprisingly good deal for Chen to stay in China with his family. Chen later criticized the deal and implied he'd been bullied by the Americans, so Locke et al. arranged a second deal for the activist and his family to relocate to the United States. All of it ended with impressively little damage to the U.S.-China relationship.

September 2012: Protesters attack Locke's car.

Nationalist outrage has a logic all its own in any country, but especially in China. That month, tension between China and Japan spiked dangerously over some tiny disputed islands. Beijing responded in part by stirring up nationalism and public anger at Japan -- never hard to do, given Japan's brutal wartime occupation of China -- probably in an effort to deflect attention from economic problems. The crowds got out of control, though, burning Japanese cars and shops thought to sell Japanese goods. At some point, it became less about Japan and more about just getting angry at foreigners. A crowd of about 50 flag-waving protesters gathered outside the U.S. Embassy and attacked Locke's car, which was clearly marked as the U.S. ambassador's. It might not have been such a big story if not for the dozens of Chinese police standing by and watching it happen without attempting to stop the crowd.