Because of the violence, which included the killing of priests, for safety the Dominican brothers began quietly to move from their church. They continued to say Mass and the sacraments, but were physically living more than 18 miles away in Bakhdida.
Not to draw attention to themselves they dressed in civilian clothes and came and went discretely to celebrate Mass in caves, "like the first Christians did in the catacombs at the beginning of the Christian era," Archbishop Najeeb said.
It was during those next few years that the brothers began to bring progressively the manuscripts out of the convent in Mosul.
Then, in 2014, the Islamic State arrived in Mosul. Under threat of death unless they converted to Islam, Christians fled the city. Stopped at checkpoints on the roads, Islamic State took everything, so they were forced to leave with only the clothes they were wearing.
Archbishop Najeeb and his brothers made it safely past the checkpoints. Then, just ten days before Islamic State invaded Bakhdida, he rescued many of the manuscripts again, this time bringing them to Erbil, where they have remained.
The documents include more than 25 subjects, including theology, philosophy, astronomy, medicine, history, and geography, many of which date back "to the 10th, 11th, and 12th century in Aramaic," Archbishop Najeeb said.
They also have documents in Syriac, Arabic, Turkish, Armenian, Hebrew, Persian, and more: "All of this makes up our collection and heritage, not only Christian but also in the international communion for the whole of humanity," he explained.
Archbishop Najeeb noted that preserving the manuscripts is far more important than merely having a record of history and an archive of historical objects, but something vital for the education of future generations as well.
"In fact, the manuscripts and the archives of these ancient document make up our history and are our roots. We cannot save a tree without saving its roots. The two can bear fruit," he said.
"So, it is important, all of these archives. This history is a part of our collective archives, our past, our history. And these we absolutely had to save, as our children."