The story
- Proto-Indo-European*upó
- Proto-Germanic*ub
- Proto-Germanic*upp
- Proto-West Germanic*upp
- Old Englishupp
- Proto-Indo-European*h₂en-
- Proto-Germanic*an
- Proto-West Germanic*ana
- Old Englishon
- Old Englishuppan
- Middle Englishupon
- English todayupon
From Middle English upon, uppon, uppen, from Old English upon, uppon, uppan (“on, upon, up to, against, after, in addition to”), equivalent to up (“adverb”) + on (“preposition”). Cognate with Old Saxon uppan (“upon”), Old High German ūfan, ūffan (“upon”), Icelandic upp á, upp á (“up on, upon”), Swedish uppå (“up on, upon”) (thence Swedish på), Danish på (“up on, upon”), Norwegian på (“up on, upon”).
Etymology from Wiktionary, CC BY-SA 4.0.