From Wikipedia on Pope Pius XII:
“While the Vatican was officially neutral during World War II, Pius XII maintained links to the German Resistance, used diplomacy to aid the victims of the war and lobby for peace, and spoke out against race-based murders and other atrocities.[2] The Reichskonkordat and his leadership of the Catholic Church during the war remain the subject of controversy—including allegations of public silence and inaction about the fate of the Jews.[3] After the war, he advocated peace and reconciliation, including lenient policies towards Axis and Axis-satellite nations. He was also a staunch opponent of Communism and of the Italian Communist Party.”
This topic was covered in Rodney Stark’s book, Bearing False Witness: Debunking Centuries of Anti-Catholic History. I would suggest reading Chapter 2, “Sins of Anti-Semitism”, pp. 9-35, specifically pp. 29-34 on “Hilter’s Pope”. Of special note:
(p.30) "As they noted, Hitler had bitterly attacked the Catholic Church, had closed all the Catholic schools, and had arrested thousands of priests and nuns and sent them to Dachau and other death camps.
As the world learned of the horrors of the Nazi death camps, Pope Pius XII was widely praised for his vigorous and devoted efforts to saving Jewish lives during the war. In 1943, Chaim Weizmann, who would become the first president of Israel, wrote: ‘the Holy See is lending powerful help wherever it can, to mitigate the fate of my persecuted co-religionists.’ Moshe Sharett, soon to be Israel’s first foreign minister and second prime minister, met with the pope during the last days of the war: ‘I told him that my first duty was to thank him, and through him the Catholic Church, on behalf of the Jewish public for all they had done various countries to rescue Jews.’ Upon the pope’s death in 1958, Golda Meir, a future prime minister of Israel, noted his efforts on behalf of the Jews of Europe, calling him ‘a great servant of peace’ for it was well-known among that generation of Israelis that Pope Pius XII had made many personal efforts to protect and shelter Jews from the Nazis."
This is such a violent time in human history. It is a time when it produced such saints as St. Edith Stein (aka St. Teresa Benedicta of the Cross) & St. Maximillian Kolbe, both who’d died at Auschwitz.
You ask: “How can we trust the acclaimed History - when It was written by Church and the Roman state combined?”
Easy: the word “Catholic” first appeared in writing by St. Ignatius of Antioch ca. 107-110 AD in the Letter to the Smyrnaeans:
"See that you all follow the bishop, even as Jesus Christ does the Father, and the presbytery as you would the apostles; and reverence the deacons, as being the institution of God. Let no man do anything connected with the Church without the bishop. Let that be deemed a proper Eucharist, which is [administered] either by the bishop, or by one to whom he has entrusted it. Wherever the bishop shall appear, there let the multitude [of the people] also be; even as, wherever Jesus Christ is, there is the Catholic Church. "
This epistle demonstrates that the Church had existed long before this supposed heretical church.