According to the author, what were condition like in europe during the 800's

Are you asking for the 800s or the 1800's (assuming you had a typo? i'll answer both anyways)

In the 800's, Charlemagne was crowned king by the pope, and Europe was under attack by all sorts of surrounding tribes, like the Vandals, Goths, Angelo-Saxons and more. It was a war zone.

In the 1800's, the economy grew, and there were more labor. More Europeans entered America and brought unknown diseases. I guess it was Europe's Industrial revolution.