Actually, the “thee”s and “thou” type stuff is early modern english. Exemplified by Shakespeare. Believe it or not, all Shakespeare words are still in our dictionary.
Middle english - Chaucer. Recognizable, but you’ll need a glossary. About a third of the words no longer used. Many different spellings. Reading it out loud you will sometimes find yourself speaking a perfect english accent due to the phonetics of the spelling.
Old english is anglo-saxon, see Beowulf. This is english before the norman invasion and is effectively a “foreign” language.
Sorry. Early modern english and redneck.
Speaking of thee and thou, you sound like you might know this answer. I read somewhere that there was a Norse? letter for ‘th’ that resembled a ‘Y’, and that when typesetting began, a ‘Y’ was often used for it, so we ended up with ‘Ye Olde..., but would have been pronounced ‘The’. Any idea about the veracity of that theory?
When I was growing up in Maryland, the Quakers used the “thee” and “thou” when speaking one to another, and occasionally my mother would use it when speaking to me or my brother. However, I don’t think they would use the word “thine” as a possessive before a work beginning with a consonant sound.