Roman numerals descended from Etruscan numerals, which descended from Greek Attic numerals. The Etruscans had symbols to represent 1, 5, 10, 100, 500, and 1,000. Around 600 C.E., the Latin alphabet and Roman numeral system were derived from those used by the ancient Etruscans.
Roman numerals were used in Europe through the late 18th century. Although we typically use Arabic numerals to represent the years on our Julian calendar, Roman numeral printed dates are commonly found in both ancient and modern book imprints. This guide will teach you first to read Roman numeral dates and then to convert standard Julian dates into Roman numeral dates.
How to Read Roman Numerals and Roman Numeral Dates
You can easily interpret Roman numerals when you understand their basic components. This section will teach you the basic Roman numerals as well as how to interpret combinations of numerals.
- Know basic Roman numeral components.
- M = 1,000
- D = 500
- C = 100
- L = 50
- X = 10
- V = 5
- I = 1
- Understand how Roman numerals are notated.
- Numbers are always written in descending order, with the largest symbol first and the smallest symbol last.
- Numbers are created according to the addition principle. For instance, the Roman numeral III = I + I + I, or 3. The Roman numeral VI = V + I, or 6.
- If a smaller numeral randomly appears before a larger numeral, then the smaller numeral is subtracted from the larger one. For example, instead of writing IIII, the Romans wrote IV, which is translated V – I, or 4.
- You will typically see the subtraction principle used for the numbers 4 and 9. You will also see the subtraction principle used when 4 or 9 are multiplied by a value of 10.
1. IV = (V -1 ) = 4.
2. XL = (L – X) = 40
3. CD = (D – C) = 400
- 3. Use the addition and subtraction principles to translate Roman numerals.
- MDCLXVI = M + D + C + L + X + V + I = 1,000 + 500 + 100 + 50 + 10 + 5 + 1, or 1,666.
- XIX = X + (X – I), or 19.
- CD = (D – C), or 400
- Recognize some arbitrary rules.
- The values V, L and D are never repeated in the same Roman numeral.
- Sometimes, the Romans used confusing shorthand. For example, VIIC could equal 700. If you see multiple lower-value symbols below a higher-value symbol, then you can guess that the writer was taking this shortcut.
- You might see a number like V with a horizontal line over the number. This means to multiply the digit by 1,000. If you see a V with a bar over it, then the author probably meant to symbolize the number 5,000.
- Read Roman numeral dates. Roman numeral dates usually consisted of a string of symbols denoting the year. Month and day were generally not relevant.
- Always read dates by applying the addition principle. For example, MMXII is the equivalent of 1,000 + 1,000 + 10 + 1 + 1, which is the same as 2012.
- When you see a smaller numeral before a larger numeral, apply the subtraction principle. For example, MCDXCII is the same as 1,000 + (500 – 100) + (100 – 10) + 1 + 1, or 1492.
Converting Julian Years to Roman Numerals
After learning to read and interpret Roman numerals, you will also want to learn to convert our Julian year numerals to Roman numerals.
- 1. Break down Julian year numerals according to place value. For example, the year 1492:
- Has a 1 in the thousands place, which represents 1,000.
- Has a 4 in the hundreds place, which represents 400.
- Has a 9 in the tens place, which represents 90.
- Has a 2 in the ones place, which represents 2.
- Substitute the appropriate Roman numeral for each digit in each place value column.
- For 1,000, substitute M.
- For 400, substitute CD.
- For 90, substitute XC.
- For 2, substitute II.
- Write the Roman numerals in descending order according to their place value. In this case, 1492 is represented as MCDXCII in Roman numerals.
Roman Numeral Dates. This resource from the Cornell University library provides a listing of Roman numerals for years ranging from 1450 to 2100. If you are struggling with a conversion, then you can find your date and its corresponding Arabic numeral year within this list.
Nova Roma. This site provides in-depth descriptions of how to read Roman numerals. The site also offers a calculator that will convert Julian years into Roman numerals.
BBC British History. This guide and set of practice problems for elementary school students from the BBC is a good way to present Roman numerals to a young audience.
Math Captain. This resource provides detailed explanation of Roman numerals as well as practice problems. Additionally, the site features live chat with online tutors in case you have questions about the problems.