when in Rome, do as the Romans do

• when in Rome, do as the Romans (less common)
• when in Rome, do like the Romans do (less common)

The first attestation is Medieval Latin si fueris Rōmae, Rōmānō vīvitō mōre; si fueris alibī, vīvitō sīcut ibī (“if you should be in Rome, live in the Roman manner; if you should be elsewhere, live as they do there”), which is attributed to St Ambrose.

Robert Burton in his Anatomy of Melancholy (1621) uses the phrase “When they are at Rome, they doe there as they see done.”[1]

when in Rome, do as the Romans do

1. (strictly) When in a foreign place, suit behavior or appearance to the local culture.
2. (loosely) Adapt to the circumstances; follow common custom.

For quotations of use of this term, see Citations:when in Rome, do as the Romans do.

• when in Rome (ellipsis, more common)

• Seferyan, S. S.; Hovhannisyan, L. V.; Lazaryan, A. A. (1986) Angleren-hayeren darjvacabanakan baṙaran [English–Armenian Phraseological Dictionary], Yerevan: University Press, page 179