He is the most famous refusenik in the world.

After nine years in Soviet prisons, he was released in a prisoner exchange, crossing the infamous Glienicke Bridge (the “Bridge of Spies”) from East Germany to West Berlin. The Soviets told him to walk straight ahead; he zigzagged — a final act of defiance. A first act of freedom.

Immediately, he made aliyah and continued to advocate for Soviet Jewry. He was the driving force behind the historic rally in December 1987 that brought 250,000 marchers (my wife and me included) to Washington, D.C., pressuring Soviet President Gorbachev to ease emigration restrictions. For his struggle to promote human rights, he was awarded the Congressional Gold Medal and the Presidential Medal of Freedom.

This biography, of course, belongs to Natan Sharansky.

But Natan’s years as a refusenik represent just the first volume in an extraordinary life.

In Israel, Natan started a new political party promoting the integration of Soviet Jews and served for many years in the Knesset. Then, in 2009, Natan became the head of the Jewish Agency for Israel, UJA’s largest overseas partner. And now, having led the Jewish Agency with enormous distinction for the last nine years, Natan is planning to step down in June.

On Wednesday evening, I had the privilege of joining hundreds who trekked through the storm to honor Natan and thank him for his work on behalf of the Jewish Agency. It was standing room only as dignitaries like President George W. Bush, Prime Minister Netanyahu, Israeli politicians from left to right, and an incredibly diverse group of people from throughout the Jewish world, reminisced about Natan and spoke to his profound impact.

For all this, Natan is remarkably soft-spoken and humble.

I witnessed this most recently last week in Israel, where I was attending board meetings of the Jewish Agency in Zichron Yaakov, a beautifully scenic town south of Haifa, overlooking the Mediterranean. On Shabbat, a group of us were having a late breakfast with Natan when our waitress, a woman in her late 20s, born in the former Soviet Union, realized who was sitting at the table. Awestruck, she told us that growing up her parents had only two pictures on the wall. One of Nelson Mandela. The other of Natan Sharansky.

Natan was incredibly kind and open with her, totally unpretentious and down-to-earth, and engaged her in conversation about her childhood. (For his kindness, he was rewarded with a piece of cheesecake, even though the kitchen was already closed.) Earlier the same day, as we entered a synagogue for morning services, a man came up to Natan and said: “You know, you look an awful lot like Natan Sharansky.” His answer, barely above a whisper, “I’ve heard that before.”

Natan is not retiring. Though he looks forward to spending more time with his wife, Avital (who famously spearheaded the campaign to have Natan released from prison), he has a vital new undertaking. Natan will be chairing an institute to train hundreds of Jewish Agency shlichim — emissaries representing the best and brightest of Israel — who come to American communities, campuses, and camps and help build connections between American Jews and Israel. Eventually, the reverse takes place; these shlichim return home with a strong appreciation of American Judaism that can be shared with their friends and communities in Israel.

At the dinner celebrating Natan this week, he said — with the wisdom of a man who has lived many lives — that the biggest threat facing Jews today is ourselves. Now that we no longer unite around issues like the fight to free Soviet Jewry, we struggle to find connections; our differences in today’s polarizing environment become more entrenched. But Natan has never shied away from a fight, and he is determined to continue working to bring us closer.

As long as this humble hero is in the trenches, there’s hope.

Shabbat shalom