Translation of "unbeatable" into Japanese

At the peak of its power, that aggressive nation seems unbeatable.

その侵略国家は全盛期にあり,無敵に見えます。

She was unbeatable, not even the great power of Egypt being able to hold her in check.

バビロンは無敵を誇り,強国エジプトさえもそれを制しえませんでした。