Why are capital i and lowercase L identical?

We are fortunate to have hundreds of fonts available on our computers, even more so if we take advantage of the resources of the Internet, but for centuries we did not have that availability. Not so long ago, with typewriters, you could tell from the context what character had been used.

Homoglyphs

A zero (0) could be an O. Sometimes the Ø was used to differentiate them, a solution as long as you did not write in any Scandinavian language or in Greek, where they can be confused with the letters Ø and Φ, respectively. The number 1 could be confused with the capital i (I) or the lowercase L (l), as well as the vertical bar (|). It did not help the reader that some typewriters did not have a key for 1 and/or 0, using the I and O as substitutes. In the case of the pleca, it could be shown separated in two continuous vertical bars (¦).

If we compare between different alphabets there are more cases, such as the semicolon (;) and the Greek question mark (;), a confusion that any programmer will fondly remember, or the lowercase italic m and the lowercase italic т (т). The latter in uppercase italic is Т. You can copy the character and alternate between normal and italic if you doubt me.

All these examples are homoglyphic. They are not limited to individual characters, but also apply when one group of these is confused with another, such as rn with m, vv with w, cj with g,cl with d and ci with a. It also happens with the metaphon or umlaut and the umlaut (¨) or with the hyphen (-) and the minus symbol (-, although it is usually shown as -).

History of letters

Having named the problem, it is necessary to go back in history to solve the question. We have to go back a few millennia, but not to the beginning of writing, but to the Romans, simply because we use the Latin alphabet. If we were to focus on homoglyphs in another alphabet or between alphabets, history would be different.

In the beginning, there were no upper or lower case letters, although in Roman monuments we see letters similar to the former. Even though the calligraphy is called Roman square capital, this being a later denomination. It was also called monumental capital. It was generally used on hard materials such as the marble of the monuments that limited the curved strokes. That is why it is characterized by its straight lines and finials.

Rustic capitals

This was adapted to manuscripts as the elegant or square capital (capitalis elegans or quadrata), which has survived in a few copies to the present day, probably used in luxury texts and venerated works due to the difficulty of tracing with calamus or pen on papyrus or parchment. For this reason the rustic capital (capitalis rustica), somewhat less formal, and its epigraphic variant (scriptura actuaria) were developed. The capital rustica was more rounded, so it was simpler to write. Its ascending and descending strokes were minimal. Only the L, B, F and, occasionally, the P, exceeded the rest in height, while the Q is the only one that descended. Its use became popular until the 6th century A.D. and was maintained in titles and headings until the 9th century A.D.

Roman cursive

Simultaneously, the Romans had the old Roman cursive, capital cursive or capital cursive and the new Roman cursive or lowercase cursive. They were used in the daily and informal sphere. The former was used until the second century A.D., while the latter was used from the third to the seventh centuries A.D. Note that we are taking the first steps towards the distinction here, but each is a distinct calligraphy. In each of the above there is no distinction between lowercase and uppercase.

Simultaneously, the Romans had the old Roman cursive, capital cursive or capital cursive and the new Roman cursive or lowercase cursive. They were used in the daily and informal sphere. The former was used until the second century A.D., while the latter was used from the third to the seventh centuries A.D. Note that we are taking the first steps towards the distinction here, but each is a distinct calligraphy. In each of the above there is no distinction between lowercase and uppercase.

Evolution of the script

Uncial calligraphy (uncialis) probably developed from the ancient Roman cursive, being used from the fourth to the eighth centuries AD for Latin, Greek and Gothic and replacing the rustic capital, which was reserved for titles and headings. Its strokes are curved due to the use of parchment and vellum, as opposed to papyrus. However, they are still considered capital letters. The letters are not linked and, over time, spaces between words, ascending and descending stems, turns and overlaps will be shown. Simultaneously, the semi-uncial calligraphy derived from a more advanced Roman cursive, being more rounded than the uncial. It was used from the 3rd century to the end of the 8th century A.D., first for pagan texts and later for transcribing Christian texts on the European continent and in Africa.

Caligrafía merovingia

After the fall of the Roman Empire, we have in France the Merovingian calligraphy or Frankish minuscule developed during the Merovingian kings of France from the 6th to the 8th century. Like the previous ones, it derives from the Roman cursive minuscule. In this case, the letters are not proportioned, they have ligatures, but no guide lines, so the lines overlap. Sentences are separated by periods and begin in capital or uncial. In short, a nightmare for legibility. 

Carolingian script

The Merovingian calligraphy does not last long, as it is replaced by the Carolingian or Carolingian minuscule used in the empire of Charlemagne during the ninth to thirteenth centuries. It derived from the semi-uncial and the Irish insular script. It was developed by the Benedictine monk Alcuin of York of Corbie Abbey in 780 AD so that the Latin alphabet of St. Jerome's Vulgate could be understood in different regions. Although it became obsolete with the Gothic minuscule, during the Italian Renaissance it was the basis for later calligraphies.

Script hierarchy

Before moving on, you will have noticed that some calligraphies do not disappear immediately with the appearance of a more modern one. This is because the texts followed a hierarchy:

1. First line in Roman square capital.
2. Next line in rustic capital.
3. Next line in uncial.
4. Introductory paragraph in semi-uncial.
5. Main text in Carolingian minuscule.

The beginnings of the following sections would have the first word in square capital or uncial and in the subsections the same thing would happen but only with the first letter. This is already similar to what we do with upper and lower case, except that it would be as if we were now changing the font instead of pressing the upper case button. That is, it starts the trend to alternate the appearance of letters in a text under certain rules, but each remains its own calligraphy. Even "uppercase" did not have to be larger than "lowercase".

Gothic

The evolution to an alphabet that included lowercase and uppercase letters began to take shape with Gothic calligraphy, used in Western Europe from 1150 to the 16th century, although in Germany and Latvia it lasted until the 20th century. This developed national variants, among others. For example, the one shown in the image is the English variant of a 1407 Malmesbury Abbey Bible. Fraktur, shown in the fourth image, is another variant. You can see that although they have similar characteristics, they are far from identical. However, the similarity of the letters lent itself to confusion.

Humanist minuscule

In the 15th century, some Renaissance humanist lawyers in northern Italy decided to return to the Carolingian minuscule, giving birth to the humanist minuscule. They did not return to the Carolingian minuscule of Charlemagne, but to that of a couple of centuries later, when it was already more uniform and compressed. Thus, we find that Gothic calligraphy or modern letters (litterae modernae) is used in universities, while humanist calligraphy or ancient letters (litterae antiquae) is used in vernacular literature. With the printing press, Venetian printers spread the humanistica minuscule, while Germany clung to Gothic until World War II.

Homoglyphic implications

In the capitoline, the I was a straight stroke and the L a right angle, the same as in the elegant and rustic capital. With the italics the perpendicular stroke of the L begins to diminish but is maintained. The uncial, Merovingian and Carolingian L maintain this arm, although its size is minimal. The main difference between the i and the L is its length, especially in the Carolingian where the i has no point. It is necessary to say that even within each of the scripts the letters are not totally uniform.

With Gothic the problem was not to confuse the i and the L, but to confuse the rest of the letters as well. The Carolingian calligraphy on which the Italian humanists based themselves had reduced the arm of the L until it was almost imperceptible. Following the trend of the hierarchy of calligraphies, the two calligraphies continued to alternate, leading to the use of upper and lower case letters to which we are accustomed.