Why is the number 4 on a clock face depicted as IIII and not as IV? In almost every other use, the Roman for 4 is IV not IIII. But although the question is simple, there is no easy or definite answer.

One common suggestion is that around the circle the IIII balances the VIII which is in its mirror-symmetrical place that is if a mirror was placed vertically between the XII and VI, the VIII and IIII would reflect on to each other.

This classic clock face shows the attraction of this theory. With the thick descending strokes and thin ascenders used in this 19th century French enamel face, the IIII and the VIII do balance each other well. But there are problems with this explanation. Although the IIII balances the VIII, the V does not balance the VII, nor the I the XI.


Another plausible explanation might be that IV has three strokes and is more likely than IIII to be confused with the neighbouring III or it could be confused with the upside down VI. Recognition is made harder by the fact that all are at unfamiliar angles to the reader. However, watch and clock faces that have no numerals show that the time is easily recognised by the angle of the hands alone.

One correspondent even suggested that Parliament held the copyright on using IV and charged a fee to any clockmaker imitating it, so hey all used IIII instead. That is, of course, nonsense. But it fills the vacuum left because none of these suggestions really offers an adequate explanation of why the normal rules of writing Roman numerals have been broken.

I think the answer is rather different. Artefacts in Wells Cathedral in Somerset, England indicate that it is the question that may be based on a false assumption. Have the normal rules of writing Roman numerals been broken? Or does the dial of a clock simply use the normal rules which were used when the clock face was first drawn in the 14th century? It is worth remembering that when the idea of a mechanism rotating hands to indicate the passage of time was invented, the means by which the pointers showed the time had to be designed.

The oldest surviving clock-face in its original condition is on the clock inside Wells Cathedral in Somerset. It dates from before 1392 and the original mechanism now in the Science Museum has some claim to be the oldest surviving clock works in the world. The current mechanism that drives it is Victorian, but the face has not been changed for more than 600 years.

Look at the official image of the clock here

On this oldest example the innermost circle shows the age of the Moon and uses Arabic numerals from 1 to 30. The next ring shows the minutes and uses Arabic numerals in groups of five 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55 with 60 at the top. The intermediate minutes are shown by vertical stroke like a I.

The outermost circle is more than six feet (1.93m) in diameter and around it, in Roman numerals, are the twenty four hours of the day noon is at the top indicated by a red star with the Roman numerals in gothic script I II III IIII V VI VII VIII IX X IX [this numeral has at some point apparently been fixed upside down] down the right hand side. Midnight is indicated by another red star at the bottom with I II III IIII V VI VII VIII IX X XI up the left hand side. Though it has to be said that the IX is not very clearly drawn, looking confusingly like a II.

But here we have the essential elements of the clock-face which have come down to us over 600 years roman numerals for the hours with the 4 indicated by IIII; minutes and days depicted by Arabic numerals.

Clearly there is much less power here in the symmetrical balance argument the dial is not symmetrical anyway. The Arabic numerals do not balance and the two or three stars in each sector of the clock-face are certainly not arranged to match those in the sector opposite. So why is IIII used instead of IV?

The answer I believe is found in manuscripts in the Wells Cathedral library. They show that the use of IIII or more precisely iiii or iiij for 4 was commonplace even though 9 was normally depicted by IX or ix. In other words, the subtractive principle was used for one but not the other.

A Chronicle of the early 12th Century certainly before 1135 shows the line of English Kings not with their dates but with the length of their reigns. Here are three from the list

Adelardus xiiii

Edouardus fili xxiiii

Aylredus ix anni et vi ebdomadibus (9 years and 6 weeks)

A hundred odd years later, in the mid 1200s, a copy of the Liber Ethinmologiarum by St. Isidore of Seville (died 636) was written out. Liber V (Book 5) lists the contents of the section Of the Lawgivers of Divine and Human Laws. The verso of folio 36 lists 39 headings. It uses iiii exclusively for 4, but ix exclusively for 9.

Pages from a 15th century service book also survive in the library. One page has notes in red ink above the text giving numbers. Again, it uses iiij exclusively for numbers ending in 4 and ix for those ending in 9. Two examples - lxxxiiij for 84 and lxix for 69.

So the clock-faces we see today could be the last surviving remnants of the style used by the mediaeval scribes when writing Roman numerals.

The practice of using IIII rather than IV on clock-faces is not universal. Even in the UK examples of IV can be found, although they are extremely rare. One is the clock in the south transept of Norwich Cathedral. Here are some others.

The well-known clock, commonly called Big Ben, at the Palace of Westminster in London, where Parliament meets, has gothic style Roman numerals round its face and the 4 is depicted as iv. It dates from the 1850s.

Strictly speaking, the hour bell is Big Ben, the clock is the Great Clock, and the tower is the Clock Tower. The building is correctly called the Palace of Westminster but most people refer to it as the Houses of Parliament.



Other examples of a four represented by IV on a clock face are rare in Britain. This clock is on the Church of King Charles the Martyr in Tunbridge Wells, Kent.

And this one is on the old Town Hall in Rochester, Kent..


However, outside the UK the position can be different. In Spain the use of IV is much more common, especially in clocks dating from the 18th and 19th century.

This odd example with the numerals upright rather than following the curve dates from the 19th century and is on the tower of the cathedral of San Nicolas in Bilbao on Spain's north coast.


In neighbouring San Sebastian the Basilica Santa Maria at the north of the town uses the IV while at the other end of the town the clock on the Catedral del Buen Pastor uses the more traditional form.


And to the south of San Sebastian, in Pamplona, where they run the bulls through the streets every day for a week in July, the Catedral de Santa Maria has this example of IV carved in stone.

Finally, Len in north west has a fine Catedral with a traditional single face on the clock on its tour. And earlier versions, shown below, also use the IIII. But note the 24 hour dial, on the left, very like the one found in Wells. Both have the four winds at the corners and the stars in the background. The version on the right is carved from oak and the numerals are cut cut out separately and nailed to the face.


This domestic example of the IV was found in a second hand shop in Len in 2005.

Clock-faces v.2.1 adding pictures and further details
15 August 2005

All material on these pages is Paul Lewis 1999-2005