上句见：Day88
The Story of Philosophy的第89句：第1章Plato第1节The Context of Plato第8段第2句：

During the great generation-long Peloponnesian war(430-400 B.C.), in which the military power of Sparta fought and at last defeated the naval power of Athens, the Athenian oligarchic party, led by Critias, advocated the abandonment of democracy on the score of its inefficiency in war, and secretly lauded the aristocratic government of Sparta. Many of the oligarchic leaders were exiled: but when at last Athens surrendered, one of the peace conditions imposed by Sparta was the recall of these exiled aristocrats. They had hardly returned when, with Critias at their head, they declared a rich man’s revolution against the “democratic” party that had ruled during the disastrous war. The revolution failed, and Critias was killed on the field of battle.
浙江大学译本：许多寡头领袖曾被流放。然而雅典最终投降，斯巴达与之达成和平协议的条件之一，便是召回所有被流放的寡头贵族。

解析

这句讲了寡头领导的处境：被流放到被召回。
1、Many of the oligarchic leaders were exiled
被流放。
许多寡头领导者都曾被流放。

2、but when at last Athens surrendered, one of the peace conditions imposed by Sparta was the recall of these exiled aristocrats.
被召回。
但是最后雅典投降，作为斯巴达强加的和平协议条件，其中有一条便是召回所有被流放的贵族。
imposed：to force someone to accept (something or yourself)
Are you imposing your values on other cultures?你是在把你的价值观强加给其他文化吗?

许多寡头领导人都曾被流放，但是最后雅典投降，作为斯巴达强加的和平协议条件，其中有一条便是召回这些被流放的贵族。

寡头贵族的这种命运因与斯巴达的战局有所变换，是因为他们有亲斯巴达的嫌疑，毕竟他们赞扬斯巴达的政体制度。