Eva Mozes Kor, who has died aged 85, was an Auschwitz survivor who lost 49 family members in the Holocaust, but angered many fellow victims of the Nazis with her willingness to forgive her persecutors.
The most notable example of this was in 2015 when she publicly embraced Oskar Groening, a former SS guard known as the "bookkeeper of death", when he was convicted of complicity in the murder of 300,000 Jews.
Eva and her identical twin sister Miriam were born at Port, Romania, on January 31, 1934 to Jewish farmers. They had two older sisters, and were 10 years old in 1944 when they and their family were deported from a regional ghetto and taken to Auschwitz.
"It was early morning and still dark outside," Eva recalled in later interviews. "There were a lot of German voices yelling orders outside and then finally, the cattle-cart doors slid open.
"They were yelling 'Raus! Raus! Schnell! Schnell!' Within 10 minutes, my father and my two older sisters had disappeared… As we were holding on to my mother, a Nazi came running, yelling at us in German shouting 'Twins! Twins!' Another Nazi came over and pulled my mother to the right while the other one pulled me and my sister to the left.
"My mother started screaming, and I remember her hand was still in the air and she was crying and I never even got to say goodbye to her. I didn't realise that would be the last time I would ever see her."
That night, the twins learnt that the rest of their family had died in the gas chambers.
The girls had been spared to serve as guinea pigs for Josef Mengele, the notorious Auschwitz doctor who conducted gruesome experiments, many of them on twins, with lethal results.
On their first evening in the camp, the girls went to a latrine where, as Eva recalled, "there were the scattered corpses of three children - naked, their bodies shrivelled and their eyes wide open. It was then I made a solemn pledge that I would do everything in my power for Miriam and me not to end up on the latrine floor."
The girls were subjected to a range of experiments. Eva was regularly drained of blood until she fainted in an experiment designed to establish how much blood a person could lose and still live.
She was injected with chemicals, the content of which she never discovered. Later, the girls discovered that had one of them died, the other would have been killed with an injection to the heart so that Mengele could carry out a "comparative autopsy" on them. Miriam, who refused to talk about what had happened to her for many years, discovered much later in life that her kidneys had never grown larger than that of a 10-year-old's. She would die of kidney cancer in 1993.
One day in early January 1945, Eva went outside to find the Germans had apparently vanished, but two weeks later SS men with machine guns drew up in a car and began spraying bullets around.
The last thing Eva remembered was the barrel of the machine gun pointing at her head, "and then I faded away". When she woke up, the Nazis had disappeared, but she found herself lying in a sea of dead bodies: "I realised that I must have fainted just before a bullet hit me."
She then heard explosions as the retreating Germans blew up the gas chambers, followed by silence. Not long afterwards, Red Army soldiers arrived.
After the war, Eva and Miriam emigrated to Israel and in 1960, Eva married Michael Kor, a fellow Holocaust survivor with whom she moved to the US, settling in Indiana.
In 1978, after the broadcast of a television mini-series about the Holocaust, she and Miriam began making contact with other survivors of Mengele's experiments.
In 1984, Eva founded Candles (Children of Auschwitz Nazi Deadly Lab Experiment Survivors) and helped set up a Holocaust museum near her home. In the early 1990s, however, a rift developed between her and some other surviving Mengele twins because of her willingness to forgive.
The turning point was a meeting in 1993 with Hans Munch, another Auschwitz physician and a friend of Mengele. "I found out that he was a real human being and a very nice man," she recalled. "I really liked him and that was a very strange feeling.
"He said the nightmare he lived with every single day of his life was watching the people dying in the gas chambers… I asked if he would go with me to Auschwitz in 1995 to sign a document saying what he did at the ruin of the gas chamber in the company of witnesses, and he said yes. Afterwards, I decided to give him a letter of forgiveness."
The discovery that she had the capacity to forgive was "tremendously empowering" and she decided to extend her forgiveness to all Nazis - including Dr Josef Mengele, whom she recalled as a man with "movie-star good looks who hummed opera tunes as he worked".
"Forgiveness," she explained, "has nothing to do with the perpetrator. Forgiveness has everything to do with the victim taking back their life. I don't have to deal with the whole issue of who did what to me and how on earth am I going to punish them and make them pay for it."
In 2015 she was one of nearly 70 co-plaintiffs at the trial in Luneburg of Oskar Groening, a former junior SS guard at Auschwitz who had been responsible for inspecting the luggage of arriving prisoners and sending money and valuables to Berlin to fund the war effort.
Unusually for such a case, Groening admitted his "moral guilt" and asked for forgiveness. After giving her own testimony, Eva surprised the court by approaching the 94-year-old defendant and publicly embracing him.
When he was given a four-year jail sentence, she objected, arguing that instead of being left to rot he should have been forced to speak publicly about his experiences to help counter the claims of Holocaust deniers.
However, 49 of the other co-plaintiffs made it clear that Eva was speaking only for herself.
Eva Mozes Kor gave talks, appeared in documentaries and wrote several books about her experiences. She led annual tours to Auschwitz, and it was during one such visit that she died in Krakow, Poland.
She died on July 4, and is survived by her husband and their son and daughter.