“When in Rome, do as the Romans do.”

What does it mean?

Act the way that the people around you are acting. This phrase might come in handy when you’re traveling abroad notice that people do things differently than you’re used to.

Where does it come from?

Henry Porter, wrote a version very similar to the present day version of the proverb in his play The Pleasant History of the Two Angry Women of Abington, in 1599:

Nay, I hope, as I have temperance to forbear drink, so have I patience to endure drink: Ile do as company dooth; for when a man doth to Rome come, he must do as there is done.”