As Islamic State group militants advanced toward this monastery perched on a mountain in northern Iraq, the monks rushed to protect a cherished piece of their heritage: Their library of centuries-old Christian manuscripts. Dozens of the handwritten tomes were spirited to safety in nearby Kurdish-ruled areas.

There they remain, hidden in a non-descript apartment in the Kurdish city of Dohuk where Christians who have fled the extremists' onslaught are living and watching over them.

The Associated Press was allowed rare access to the library, a collection of copies of Bibles and biblical commentaries, mostly written in Syriac — a form of the ancient Semitic Aramaic language — and mostly dating back 400-500 years. The oldest is a copy of the letters of Saint Paul, some 1,100 years old. The bound tomes, some with tattered pages written in black and red ink, lay on shelves.