We can see Roman numerals all around us: on monuments and buildings, on clock faces, on copyright date stamps at the end of TV shows. Elsewhere, they might add a degree of gravitas to the titles of monarchs and movie sequels.
While there are no prizes for guessing where these numerals were developed and widely used – the clue’s in the name – their origins are a little murkier. It seems the Romans adopted the numerical system used by the Etruscans, although unlike the Etruscans they chose to read from left to right, rather than right to left.
An early example existed on the Rostral Column of Gaius Duilius, erected in the Roman Forum to commemorate a victory against Carthage at the battle of Mylae in 260 BC. A symbol looking something like (((I))) can be seen multiple times, each one representing the amount ‘100,000’.
What are the Roman numerals?
There are seven Roman numerals in wide use today: I, V, X, L, C, D and M, representing the numbers 1, 5, 10, 50, 100, 500 and 1,000, as set out in the chart below.
Even though the idea was pinched from the Etruscans, these Roman numerals did not come fully formed. The Etruscan system, as well as being read in the opposite direction, also used different symbols, including several for larger numbers that have defied translation.
Nor did the Roman numerals all appear at the same time. The Roman L and D (50 and 500) didn’t appear until the later years of the Republic, for example.
What are the Roman numerals for 1 to 100?
The numbers you’ll see on a clock face, one to 12, are written out in Roman numerals as I, II, III, IV, V, VI, VII, VIII, IX, X, XI and XII. Here’s another chart to take you all the way to 100:
How do you read Roman numerals?
Roman numerals are written from left to right, and they should be read in that direction, bearing in mind two rules on translation:
- When a symbol is of lesser value than the one after it, subtract the smaller value from the larger one
- When the symbol is of equal or greater value than one after it, add the two together
So, for example, IX translates as nine, but XI reads as 11, and XX is 20.
When you have longer strings of numerals, you have to account for each group of numerals separately and tally them at the end. So, while the year that Magna Carta was sealed (1215) becomes a straightforward MCCXV (1,000 + 100 + 100 + 10 + 5) the year that Julius Caesar was assassinated (44 BC) is written as XLIV, or ((50-10) + (5-1)).
This content was written for BBC History Revealed and published on HistoryExtra in MMXX (2020)