From what I have studied, though I didn't put a lot of effort into it.
Around 1400's christians were taking the athiest to task for using Jesus Christ as a swear word cause athiest don't believe in God and Jesus being God.. So the quick reply was to an Arbitrary letter to say to the christians , "you have your Jesus Christ we have our Jesus H. christ."
From what I have found that there was a Jesus Q. Christ and a Jesus R. Christ before the final globally accepted Jesus H. Christ came about.