Prince Philip has broken a 60-year public silence about his family's links with the Nazis.
In a frank interview, he said they found Hitler's attempts to restore Germany's power and prestige 'attractive' and admitted they had 'inhibitions about the Jews'.
The revelations come in a book about German royalty kowtowing to the Nazis, which features photographs never published in the UK.
They include one of Philip aged 16 at the 1937 funeral of his elder sister Cecile, flanked by relatives in SS and Brownshirt uniforms.
One row back in the cortege in Darmstadt, western Germany, was his uncle, Lord Mountbatten, wearing a Royal Navy bicorn hat.
Another picture shows his youngest sister, Sophia, sitting opposite Hitler at the wedding of Hermann and Emmy Goering.
Explaining the attraction of the Nazis, 84-year-old Prince Philip told an American academic: "There was a great improvement in things like trains running on time and building. There was a sense of hope after the depressing chaos of the Weimar Republic.
"I can understand people latching on to something or somebody who appeared to be appealing to their patriotism and trying to get things going. You can understand how attractive it was."
He added that there was 'a lot of enthusiasm for the Nazis at the time, the economy was good, we were anti-Communist and who knew what was going to happen to the regime?'
Philip stressed that he was never 'conscious of anybody in the family actually expressing anti-Semitic views'. But he went on to say there were 'inhibitions about the Jews' and 'jealousy of their success'.
Philip was born Prince of Greece and Denmark on Corfu in 1921, the youngest of five children and the only son of Prince Andrew of Greece and Princess Alice of Battenberg. All four of his sisters married German princes and three - Sophie, Cecile and Margarita - became members of the Nazi party.
Sophia's husband, Prince Christoph of Hesse, became chief of Goering's secret intelligence service and they were frequent guests at Nazi functions.
Philip went on to fight with distinction for the Allies in the Second World War before marrying the young Princess Elizabeth in 1947, five years before she became Queen. He served with the Royal Navy where, by 1945, he had risen to the rank of first lieutenant on a destroyer and was mentioned in despatches.
All of his sisters and brothers-inlaw are now dead but he keeps in contact with his German relatives.
His comments on the family's Nazi connections appear in Royals and the Reich, by Jonathan Petropoulos, to be published in Britain in May.