Any new supplies were 220/380 V 50 Hz by 1920 or so but older DC supplies and 127/220 V 50 Hz (TN-C or TT) survived much longer. In fact, there are still some 133/230 V systems (Y secondary but if there's a neutral supplied it's not used except as a PEN since there are no 133 V loads anywhere). In this case you have the same situation as in Norway - within the same city blue can be neutral or live at 133 V to earth.
TN-C with a jumper from earth to neutral in each socket and at each light fixture was fairly common in many European countries. West of the Iron Curtain it was generally banned for new work in the 1970s, on the eastern side much later. Eastern Germany had it until Aug. 1990, i.e. up to the point where the German Democratic Republic ceased to exist. In Western Germany it was banned in 1973, in Austria in 1976. In theory you can't even rent out an apartment with TN-C in Austria these days because the tenant protection law clearly states that newly-rented apartments must have all socket circuits protected by at least one 30 mA RCD but few people care (the law has been in effect for almost ten years and now landlords are slowly getting their heads around it - three years ago I was told by an electrician just to skip the required testing, no one would ever ask for the report!).
