Far from being pro-Hitler, the wartime pope Pius XII used to get up in the middle of the night and perform exorcisms on the German dictator, believing him to be possessed by the devil.

This and other contradictory behaviour by the late Pope is claimed in a new book by renowned Catholic scholar Gerard Noel in his book, Pius XII — The Hound of Hitler. In the book, to be published next month, the former Catholic Herald editor says the Pope was “not anti-Jewish or pro-Hitler”, but was motivated by “huge ambition for the Catholic Church, which he believed to be the one true Church”.

Pope Pius XII

“Pius XII was a disaster for the Jews, not because he was antisemitic, but because he had great political ambitions,” Mr Noel said. “His attitude was also moulded by the fact that he was a product of the pre-Vatican Council Church, which believed in the conversion of the Jews to Christianity.”

Mr Noel also examines in detail the fateful impact of the Concordat of 1933 between the Holy See and the Third Reich, which led directly to Hitler’s ascent to power. “Until the Concordat, Germany’s Catholic Church had been strongly opposed to Hitler. In return for widespread material concessions for the Catholic Church in Germany, the Holy See guaranteed that German Catholics would refrain from all partisan political activity. This involved the disbandment, by papal directive, of the German Centre [Catholic] Party. The party held the balance of power, and without them, Hitler was able to assume supreme power,” Mr Noel said.

“Within days of the Concordat, Hitler began his round-up of the Jews. And once he had signed the Concordat, Pius was afraid that if he criticised Hitler or Nazism, he would split the Catholic Church in Germany,” added Mr Noel, a vice-president of the Council of Christians and Jews.

“Pius had a great worldwide concept of the church as a triumphant body of great power. With the Concordat, he gained materially but lost morally.”

The book also reports a platonic, 40-year relationship between the Italian-born Pope and a German nun, Sister Pasqualina, who nursed him when he had a nervous breakdown while serving as Papal Nuncio in Germany in the 1920s, and who remained his confidante and nurse for 40 years.

“She was a very powerful and very enlightened woman, and was fervently against the Pope’s alliances with Hitler and Mussolini, but he disregarded her advice over Hitler,” Mr Noel said.

The author also believes that Pius’s nervous breakdowns made him emotionally too weak to confront Hitler.

“He couldn’t stand up to the psychological impact of Hitler and other powerful Nazis. He definitely allowed anti-Judaic attitudes to continue in the Church, and did nothing to halt those attitudes. There was a feeling that ‘the Jews could look after themselves’.”

Mr Noel, who met Pius in the 1950s, said the book was intended to defend him “against the worst accusations of antisemitism” levelled against him.