Wikipedia came through when I googled "grammar articles" - this morning's inspiration.
Etymology
Linguists believe that the common ancestor of the Indo-European languages (i.e., the Proto-Indo-European language) did not have a definite article. Most of the languages in this family do not have definite or indefinite articles; there is no article in Latin, Sanskrit, Persian, nor in some modern Indo-European languages, especially in Slavic languages — Russian, Polish and Czech, etc., nor in the Baltic languages — Latvian, Lithuanian and Latgalian. (The only Slavic languages that have articles are Bulgarian and Macedonian.) Errors with the use of the and other determiners are common among people learning English (e.g., native Czech-speaker Ivana Trump, first wife of Donald Trump, referring to him as "the Donald"). Classical Greek has a definite article, but Homeric Greek did not. In the etymologies of these and many other languages, the definite article arose from a demonstrative pronoun or adjective changing its usage; compare the fate of the Latin demonstrative "ille" (meaning "that") in the Romance languages, becoming French le, la, l’, and les, Spanish el, la, lo, los, and las, Italian il, la, lo, l’, i, gli, and le, and Portuguese o, os, a, and as.
In some languages, such as Icelandic, Norwegian and Romanian, the definite article is not always a separate word but is sometimes attached to the end of the noun it governs:
hestur, horse: hesturinn, the horse (IS) stol, chair: stolen, the chair (N) drum, road: drumul, the road (RO)
The and that are common developments from the same Old English system. Old English had a definite article se, in the masculine gender, seo (feminine), and þæt (neuter). In Middle English these had all merged into þe, the ancestor of the Modern English word the.
In Middle English the (þe) was frequently abbreviated as a þ with a small e above it, similar to the abbreviation for that, which was a þ with a small t above it. During the latter Middle English and Early Modern English periods, the letter Thorn (þ) in its common script, or cursive, form came to resemble a y shape. As such the use of a y with an e above it as an abbreviation became common. This can still be seen in reprints of the 1611 edition of the King James Version of the Bible in places such as Romans 15:29, or in the Mayflower Compact. Note that the article was never pronounced with a y sound, even when so written.
