Born in Stockholm, Sweden, his mother Maj Wising was the daughter of the first professor of neurology in Sweden. His father Raoul Oscar Wallenberg was an officer in the Royal Swedish Navy but died of cancer three months before the birth of his son. Raoul Gustav was the nephew of Marcus Laurentius Wallenberg (1864-1943), the Swedish financier who was managing director of Stockholm's Enskilda Bank.
Raoul Wallenberg was educated at the gymnasium and graduated with honours in Russian and drawing in 1930. After nine months of compulsory military service he went to France to further his education. He became fluent in French, English, German, Russian, as well as Swedish. In 1931 he went to Ann Arbor, Michigan, to study for a degree in architecture which he obtained in 1935. He then went to Cape Town, South Africa, to take a job as a salesman of building materials with a Swedish building firm.
He then worked at a bank in Haifa, Palestine, where he met Jewish refugees from Nazi Germany. In 1936 he entered a partnership with Koloman Lauer, a Hungarian Jew, running an import-export company. After 1939 this involved business trips to Germany, Hungary, and Nazi-occupied France. The American War Refuge Board and the Swedish government sent Raoul Wallenberg to Budapest to organise a rescue plan for Jews at risk.
Raoul Wallenberg did not use traditional diplomacy. He more or less shocked the diplomats at the Swedish legation with his unconventional methods. Everything from bribes to extortion threats were used with success. But when the rest of the staff of the legation saw Wallenberg's results, he quickly got their unreserved support. He has been credited with saving about 100,000 Hungarian Jews by handing out Swedish protection passports (Schutz-pass) and arranging "Swedish houses" offering Jews refuge.
On 17th January 1945, after the occupation of Hungary by Soviet troops, he was arrested in Budapest by Soviet NKVD secret police and taken to Soviet Headquarters from which he did not return. Later investigations revealed that by 6th. February 1945 he was in a jail in Moscow. After the War the Russians were repeatedly asked what had happened to him and they eventually produced a document signed by Smoltsov, the head of the Ljubyanka prison hospital, stating that Raoul Wallenberg had died of a heart attack in July 1947. However, testimonies by ex-prisoners suggested that he was still alive in the 1950s, and he was rumoured to be still alive in the 1970s.
In 1949 Albert Einstein nominated Raoul Wallenberg for the Nobel Peace Prize. In 1953 a tree in the Avenue of the Righteous in Yad Vashem, Israel, was planted to honour his memory after he was officially named a Righteous Gentile. He was made an honorary citizen of the USA in 1981, of Canada in 1985, and of Israel in 1986. A statue of him was erected in Great Cumberland Place, London. However, as his homosexuality came to be known about, he faded from prominence as a hero of the Holocaust. A new hero was found in the form of Oscar Schindler.
He had a half-sister Nina Lagergren who spent 55 years after 1945 trying to establish what happened to Raoul Wallenberg. In 1991 a Swedish-Russian inquiry into Raoul Wallenberg was set up. In 2000 the Russians admitted that after his arrest in Budapest he was a "victim of Soviet repression", which is typically a euphemism for torture and murder by the secret police.
On 12th. January 2001 the report of the Swedish-Russian investigation was published but it did not reach a definitive conclusion. The Russians continue to claim that he died in Russian captivity on July 17, 1947.