WASHINGTON — Rep. Tom Lantos, who escaped the Nazis and grew up to become a forceful voice for human rights all over the world, has died. He was 80.

The California Democrat, the only Holocaust survivor to serve in Congress, died early yesterday at the Bethesda Naval Medical Center in Maryland, his spokeswoman, Lynne Weil, said. He disclosed last month that he had cancer of the esophagus.

At his side were his wife of nearly six decades, Annette, his two daughters, and many of his grandchildren and great-grandchildren. Annette Lantos said in a statement that her husband’s life was “defined by courage, optimism, and unwavering dedication to his principles and to his family.”

Lantos, who chaired the House Foreign Affairs Committee, was serving his 14th term in Congress. He had said he would not seek reelection in his Northern California district, which takes in the southwest portion of San Francisco and suburbs to the south.

“Tom was a man of character and a champion of human rights,” President Bush said in a statement. “After immigrating to America more than six decades ago, he worked to help oppressed people around the world have the opportunity to live in freedom.

“Tom was a living reminder that we must never turn a blind eye to the suffering of the innocent at the hands of evil men,” Mr. Bush said.

Lantos assumed his committee chairmanship when Democrats retook control of Congress. He said at the time that in a sense his whole life had been a preparation for the job — and it was.

Lantos, who called himself “an American by choice,” was born to Jewish parents in Budapest, Hungary, and was 16 when Adolf Hitler occupied Hungary in 1944. He survived by escaping twice from a forced labor camp and coming under the protection of Raoul Wallenberg, the Swedish diplomat who used his official status to save thousands of Hungarian Jews.

Lantos’s mother and much of his family perished in the Holocaust. That background gave Lantos a unique moral authority that he used to speak out on foreign policy issues, sometimes courting controversy. He advocated for human rights in Sudan, Burma, and elsewhere, and in 2006 was one of five members of Congress arrested outside the Sudanese Embassy protesting what the Bush administration describes as genocide in Darfur.

Lantos’ end came faster than his many friends and admirers had expected.

“Tom Lantos was a true American hero. He was the embodiment of what it meant to have one’s freedom denied and then to find it and to insist that America stand for spreading freedom and prosperity to others,” Secretary of State Rice said. “He was also a dear, dear friend and I am personally quite devastated by his loss.” House Speaker Pelosi, a California Democrat, said Lantos used his committee chairmanship “to empower the powerless and give voice to the voiceless throughout the world.”

Flags at the White House and Capitol were lowered to half-staff in Lantos’s honor. Majority Leader Reid, a Democrat from Nevada, and Minority Leader McConnell, a Kentucky Republican, both delivered remembrances on the Senate floor.

Upon announcing his retirement last month, Lantos said: “It is only in the United States that a penniless survivor of the Holocaust and a fighter in the anti-Nazi underground could have received an education, raised a family, and had the privilege of serving the last three decades of his life as a member of Congress.”

Lantos and his wife had two daughters, Annette and Katrina, who between them produced 18 grandchildren. One grandchild died young. According to Lantos, his daughters fulfilled their promise to produce very large families because his and his wife’s families had perished in the Holocaust.