This is an idea that fascinates me and it goes beyond literature. it certainly includes history. One of my favorite examples is cuneiform tablets. Less than 10

This is an idea that fascinates me and it goes beyond literature. it certainly includes history. One of my favorite examples is cuneiform tablets. Less than 10% of the 500k to 1m tablets recovered have ever been translated. These are particularly interesting because they're some of the earliest examples of surviving written records we have. The Hittite capital Hattusa (IIRC) was lost for millenia. When it was found it was a veritable treasure trove including personal correspondence between the Hittie king and the Egyptian pharoah Ramses II. Nineveh was sacked at one point. A massive fire destroyed the library but baked the clay tablets preserving them. In the early days of Rome, Rome (the city) was sacked by Gauls. This destroyed a lot of the early works of Rome. This affected Rome's expansion (eg Caesar's conquest of Gaul has been argued to be affected by the cultural significance of this sacking). I's one reason why the origins of Rome are somewhat steeped in myth and legend rather than fact such as the apocryphal tale of Romulus and Reemus. Another example are the histories of Alexander the Great. Alexander died under mysterious circumstances at the height of his power (in his early 30s). Several primary sources were written by his inner circle. None have survived. We know this because a Roman named Arrion some 2 centuries later wrote about the campaigns of Alexander citing 3 such sources (all lost) comparing what they agreed on and what they didn't. A lot was lost in the Arab sacking of the Libary of Alexandria. I somewhat agree with some other commenters in that literary significance is more... relative. Put another way: part of their cultural significance comes from them being known, studied, performed and repaeted over centuries.