It is called a tittle, according to an email I once received. And it is over both the “I” and “J” probably because they once were the same letter, I assume. And that is about all I know.
I recall reading once a long time ago that uppercase letters were once all we had. Then some monk or someone in the middle ages developed our lowercase letters, but I’m not sure how or from what.
Could someone tell me what exactly is the dot over the lowercase “I” and “J” for? Or at the very least, could someone tell me where it came from?
So the short answer seems to be that because an i is just one line, it’s easy to mistake it for part of an adjacent letter. E.g., confusing “in” for “m”. Hence, the tittle, to make the i stand out more.
Medieval lettering was generally made up of specific downstrokes and upstrokes, something like the slash and backslash. Spaces weren’t used between letters. Thus, the word “minum” would be done as follows:
\\\//\\
The “MIN” thus is six downstrokes. It also looks exactly like “NIM.” So to tell the difference, scribes put a dot above the I.
\\i\//\\
The dot makes the word clear (It’s easier to see in actual script than on a computer, of course).
When “j” was added to the language (it is the newest letter in the alphabet), it was added just after i, and was based on the i, so it kept the dot.
“Jot” and “tittle” refers to Hebrew and Aramaic writing. Jot comes from the letter name yod, which is the smallest letter. It’s only a small mark compared to the other letters. “Tittle” in Hebrew and Aramaic writing, IIRC, is the tiny serif sticking up from the top of the letter. You know how Hebrew square writing has a horizontal top line? The tittle would be that little serif that begins or ends the pen stroke and points up from the top line. There’s also a tittle at the lower right corner of the letter bet, which is the only way to tell it apart from the letter kaf.
Jot comes from Greek iota. Note that when “jot” is used to denote character “j”, it’s pronounced as how you would say “yot” in English. This is because in Latin, from which the difference originates, and in most languages in Europe, letters i and j sound very similar, as ii and jii, and jot sort of underlines the fact that they are, indeed, two different letters. I understand that French language at some point changed the letter j to sound like dz and this, like other pronunciation weirdnesses, then migrated to English. Thus German words “Ja” and “Jahre” have English equivalents “Yes” and “Year”, as y has to be used in the place of j. See German alphabet for more. Other languages influenced by German at some point, like Estonian, can also use the jot.
If you could consider the Carolingian mini-renaissance the “Dark Ages.” It was a little burst of literacy in the 9th century, when the book hands were developed. The credit traditionally goes to an English monk named Alcuin who was hired by Charlemagne as something like the Minister of Literacy.
By “book hands” I mean the type of script they used that was supposed to be both easily writable and legible. Such scripts included the rounded uncials that developed into our modern lower-case letters. It seems the Roman alphabet was all uppercase until Alcuin’s time. If I’m not mistaken, I think the comparable Greek lowercase script was being developed in Byzantium around that time, or was it earlier? I wonder if knowledge of Byzantine script might have inspired Alcuin.
