Giorgio Vasari was the first to describe it as Gothic, a derogatory reference to the Barbarians, thought to have destroyed Classical civilization.
1. thought to have destroyed Classical civilization，是过去分词短语，作 Barbarians（野蛮人）的非限制性定语。
2. thought 之前不可能省略原形，如果补充完整，则是一个非限制性定语从句：who were thought to have destroyed Classical civilization. 不定式使用完成体to have destroyed 表示动作早于 thought。破坏古典文明，在被认为之前就已经发生。
