Nobody in olden times ever said “ye olde”. In a sign like Ye Olde Tea Shoppe the Y is standing in for a lost letter, thorn, þ, which spelled the sound at the start of “the”. By the fourteenth century scribes had worn it down until it lost its tall stem, and when printing reached England in the 1470s the type came from the Low Countries, cut for Latin, French and Dutch, with no thorn in the case. Printers used the letter that looked nearest, which was y. So “ye” was read “the” for well over a century; the first King James Bible, in 1611, still prints it in places, along with “yt” for “that”.

What I like is how completely the stand-in won. Thorn faded out of English, and once nobody remembered it, readers took the y at face value and gave the word a new sound. The best-known antique word in English is a typesetting workaround, mispronounced. Thorn itself is still alive in Icelandic, where it begins the way you say thank you: þakka þér.