のもとで

under

→ の
phrase Rare #33,249
under Used for being under someone's guidance, authority, or care, or under particular conditions. It is relatively formal.
JA: 専門家の指導のもとで訓練を受けています。
EN: I am training under the guidance of an expert.

いかなる状況のもとで王女王位継承することはあるまい

Under no circumstances will the princess inherit the throne.

ブラウン先生のもとで数学学びました

I studied mathematics under Professor Brown.

トム祖父母のもとで育てられた

Tom was raised by his grandparents.

のもとですべての人は平等

Everyone is equal under the law.

だからのもとで何年も仕事をしていたんです

That’s why I worked under him for many years.

— Article 15 (2019)