。
Under the law, all people are equal.
Literal
Law [possessive-の] foot-[in-では], all [possessive-の] people [topic-は] equal-[assertion-だ]
のもと ('under, at the feet of, beneath') is a fixed phrase meaning 'under the authority/influence of'. 法のもと(に) = 'under the law'. Echoes a clause from Article 14 of the Japanese Constitution guaranteeing equality before the law.