“Ye” was the second-person, plural, personal pronoun (nominative), spelled in Old English as "ge". In Middle English and Early Modern English, it was used to address an equal or superior person.
It is also common today in Ireland's Hiberno-English to distinguish from the singular "you".
"Ye" is also sometimes used to represent an Early Modern English form of the word "the". In this transcription the letter which resembles a 'Y' is actually a thorn, the predecessor to the modern digraph "th".
This orthography often leads speakers of Modern English to pronounce "ye" as /ji:/. However, it’s still fun when you misspell it, it makes it sound more interesting.