"O" as in O Great King

[tedholzman]

I'm kindof interested in "O". It seems to function as a form of direct address, like the vocative case in Latin. (Lewis Carroll makes fun of it in Alice: "but she remembered having seen in her brother's Latin Grammar, 'A mouse—of a mouse—to a mouse—a mouse—O mouse!')" But I can't find any useful etymological information. It certainly existed in Middle English. I can't find an Anglo-Saxon usage.

[Dr. Goodword]

This is just an alternate spelling of oh, about which very little is known.