From what I understand, the Son of God's name was allegedly Yeshua in Hebrew (or Aramaic??). Where did the (Latin?) name Jesus derive from, and why wasn't it Joshua or just the original Yeshua instead?
It comes from the greek name for jesus, "iesous". Greek was a dominant language for the early christian church, and the early missionaries. From there, it jumped to latin as "iesus". English around the 17th century started spelling these "i" s and "'y's as 'j', which was developed as a letter to reflect changing pronunciation.
'i' 'y' and 'j' do weird things between european languages. A similar example is how Jana is prounounced Yana in a lot of more latin influenced and eastern european languages but a hard J in english.
Pretty much, middle english speakers at some point decided a 'j' sound was superior. This shift happened independent of other languages, and it's kinda unique to english in europe. The letter 'i' was long used to represent both a consonant and vowel sound, so they made a new letter for the latin alphabet around the 1600s.
I dunno why that was a different evolution of 'yehoshua' familiar from the old testament even though that was almost certainly the same two names or variants there of in the original languages. My guess is that the septuigint wasn't adopted into common christian use until after it had spread through the mediterreanean, so an oral tradition with limited circulation of the gospels suddenly encountering an established text with a different translation history.
It's also interesting to note that a lot of east african churches where christianity spread a long time ago know jesus as yeshua or prounounced "yesou" in the greek fashion.
u/Georgy_K_Zhukov wrote about this a couple of weeks ago in an answer to a similar question: