Why Was 'J' the Last Letter Added to the Alphabet?

The English alphabet, as we know it today, has undergone various transformations before reaching its current form. Among its 26 letters, "J" holds the distinction of being the last to be added. This development in the alphabet's history sheds light on the evolution of language and orthography over the centuries.
The Evolution From I to J
Children's book from 1743, showing I and J considered the same letter.
Historically, "J" began as a mere variation of the letter "I." In ancient Roman times, "I" served dual purposes, representing both a vowel and a consonant sound, similar to the modern English usage of "Y." Even in the original 1611 King James Version of the Bible, names that we now spell with a "J," like James and Jesus, were recorded as "Iames" and "Iesous," respectively. The need for a distinct consonantal sound became evident, particularly in Latin, the precursor to many modern European languages. This need led to the elongation of the "I" in certain positions, primarily at the beginning of words or numerals, giving rise to a new symbol.
The Renaissance and Grammatical Reformation
The transformation of "J" from a stylistic flourish to a recognized letter was significantly influenced during the Renaissance. Gian Giorgio Trissino, an Italian Renaissance grammarian, was pivotal in this evolution. In 1524, Trissino explicitly distinguished "I" from "J" in his writings, promoting "J" to represent a consonantal sound, thus marking its formal inclusion in the alphabet. This distinction was crucial for accurate phonetic representation in writing, especially for the Italian language, which influenced its adoption in other European languages.
Gian Giorgio Trissino, portrayed in 1510 by Vincenzo Catena.
Adoption Into the Alphabet
Following Trissino's advocacy, the use of "J" spread gradually among scholars and printers throughout Europe. By the 17th century, the letter was universally recognized in the English language and was officially documented as distinct from "I" in a publication from 1633, solidifying its place in the alphabet.
The addition of "J" to the alphabet is a testament to the dynamic nature of language and its adaptability in response to phonetic necessities. Its journey from a numeral marker to a fundamental element of the alphabet highlights the interplay between linguistic evolution and cultural shifts over a millennia.
References: THIS WAS THE LAST LETTER ADDED TO THE ALPHABET | The Letter J was Actually the Last Letter Added to the Alphabet?