From the seventh century, the common Norse language began to undergo changes that did not spread to all of Scandinavia, resulting in the appearance of two dialect areas, Old West Norse (Norway and Iceland) and Old East Norse (Denmark and Sweden). Most of the changes separating East Norse from West Norse started as innovations in Denmark, that spread through Scania into Sweden and by maritime contact to southern Norway. A change that separated Old East Norse (Runic Swedish/Danish) from Old West Norse was the change of the diphthong "æi" (Old West Norse "ei") to the monophthong "e", as in "stæin" to "sten". This is reflected in runic inscriptions where the older read "stain" and the later "stin". Also, a change of "au" as in "dauðr" into "ø" as in "døðr" occurred. This change is shown in runic inscriptions as a change from "tauþr" into "tuþr". Moreover, the "øy" (Old West Norse "ey") diphthong changed into "ø", as well, as in the Old Norse word for "island". This monophthongization started in Jutland and spread eastward, having spread throughout Denmark and most of Sweden by 1100.