2513: I Longum: ꟾ Oct 29, 2021

Latin vowels used to be written with apexes, which looked more like traditional accent mark than the macrons used for writing out long vowels in Latin today. This was the only form of punctuation, if it can even be called that, sine historically Latin had no lower-case, no spaces words or breaks for sentences. The only other variable in this system was 'i longum' or 'long i', written as ꟾ which represented the long vowel but didn't take the accent mark. While it is true that J developed from I, it is more accurate to say that J developed from ꟾ. Moreover, in Latin orthography, if two i's would be written together, the second would be ꟾ to distinguish it from N or even U (V). Likewise, in Dutch, there is a common digraph for the long [iː] sound written as IJ, and often further stylized with a smaller i in front, sometimes written as Y, though the Y was not related historically.