It started with Yochanan (Hebrew) -> Ioannis (Greek) -> Johannes (Mediaeval Latin) -> Jon (Middle English), but now every language seems to have a version, e.g. * Hans * Joanna * Hanna * Jan * Ivan/Ivanka * Vanja * Jens * Sean/Shaun/Shawn/Shane * Joan/Jane/Jean/Janis * Evan/Ewan * Jock/Jack * Ian/Iain/Ianto * Juan * Yiannis/Gianna * Gianni/Giovanni/Vanni/Giovanna * Jonas * Ivo/Iva * Eoin/Owen * Seonaid/Siubhan and those are just the ones I’ve heard used, there are hundreds more!