When in Rome, do as the Romans do . . . well, I’m in Rome.

I arrived here this morning on a train from Milan. According to some of my Milanese friends, I am a long ways from home. Rome, after all, is south of the River Po.

So, what does Milan have to do with Rome? Well, for one – ‘when in Rome, do as the Romans do’ – has its origins in none other than the city of Milan. The phrase, which encourages people to act according to local customs, is derived from advice that St Ambrose (c. 339-397 CE), the patron saint of Milan, gave to St Augustine (354-430 CE), while the latter was living in Milan with his mother, St Monica (331-387 CE).

What exactly were the Romans doing in the first place? Well, they were fasting. Specifically, they were fasting on Saturdays, a practice that was not followed in Milan, which today still uses a different (Ambrosian) liturgical rite than Rome. The discrepancy did not bother Augustine, but it bothered Mother Monica. So, the dutiful son turned to the bishop of Milan for advice. Augustine records the conversation in his letter to Januarius (Augustine, Epistula 54):

‘When my mother followed me to Milan, she found the Church there was not fasting on Saturday. She began to be troubled, and to hesitate as to what she should do; upon which I, though not taking a personal interest then in such things, applied on her behalf to Ambrose, of most blessed memory, for his advice. He answered that he could not teach me anything but what he himself practiced . . . “When I visit Rome, I fast on Saturday; when I am here, I do not fast. On the same principle, observe the custom prevailing in whatever Church you come to, if you desire neither to give offence by your conduct, nor to find cause of offence in another’s.” When I reported this to my mother, she accepted it gladly’ (54.3).

Augustine, himself, was not displeased with the advice: ‘And for myself, after frequently reconsidering his decision, I have always esteemed it as if I had received it by an oracle from heaven’ (54.3).

For both Ambrose and Augustine, if a practice or custom was not prescribed by the authority of scripture or by the tradition of the universal Church, the issue was ultimately insignificant:

 ‘There is no better rule for the wise and serious Christian in this matter, than to conform to the practice which he finds prevailing in the Church to which it may be his lot to come. For such a custom, if it is clearly not contrary to the faith nor to sound morality, is to be held as a thing indifferent, and ought to be observed for the sake of fellowship with those among whom we live’ (54:2).

Meanwhile, back in Rome, my Thursday arrival has coincided with Ascension Day, one of the major Catholic feast days of the year – it is certainly not a day of fasting. Having no desire to go hungry here in the Eternal City, I shall spend the day doing as the Romans.


‘When in Rome’ continues to inspire the romantic imagination of modern pop culture. Films released in 1952, 2002 and 2010, and a number of publications, including a Catwoman comic book series, bear the name, while in the world of music, Billy Joel, Nickel Creek, Travis Tritt and Barbra Streisand have all recorded songs carrying the title.


Ambrose’s advice ‘do as the Romans’ appears in two of Augustine’s letters. Along with the letter to Januarius (Epistula 54), cited above, it is also found in his letter to Casulanus (Epistula 36):

‘Since, we do not find in the Gospels or in the apostolic writings that any law was laid down as to fasts to be observed on particular days. . . I will tell you the answer given to my questions on this subject by the venerable Ambrose Bishop of Milan, by whom I was baptized. When my mother was with me in that city, I, as being only a catechumen, felt no concern about these questions; but it was to her a question causing anxiety, whether she ought, after the custom of our own town, to fast on the Saturday, or, after the custom of the Church of Milan, not to fast. To deliver her from perplexity, I put the question to the man of God whom I have just named. He answered, “What else can I recommend to others than what I do myself?” When I thought that by this he intended simply to prescribe to us that we should take food on Saturdays—for I knew this to be his own practice—he, following me, added these words: “When I am here I do not fast on Saturday; but when I am at Rome I do: whatever church you may come to, conform to its custom, if you would avoid either receiving or giving offence.” This reply I reported to my mother, and it satisfied her, so that she scrupled not to comply with it; and I have myself followed the same rule. Since, however, it happens, especially in Africa, that one church, or the churches within the same district, may have some members who fast and others who do not fast on the seventh day, it seems to me best to adopt in each congregation the custom of those to whom authority in its government has been committed’ (Epistula 36.32).