According to Identity doctrine, 2 Esdras 13:39–46 then records the history of the nation of Israel journeying over the Caucasus mountains, along the Black Sea, to the Ar Sereth tributary of the Danube in Romania ("But they formed this plan for themselves, that they would leave the multitude of the nations and go to a more distant region, where no human beings had ever lived. … Through that region there was a long way to go, a journey of a year and a half; and that country is called Arzareth"). The tribes prospered, and eventually colonised other European countries. Israel's leading tribe, the Tribe of Dan, is attributed with settling and naming many areas which are today distinguished by place names derived from its name – written ancient Hebrew contains no vowels, and hence "Dan" would be written as DN, but would be pronounced with an intermediate vowel dependent on the local dialect, meaning that "Dan", "Den", "Din", "Don", and "Dun" all have the same meaning. Various modern place names are said to derive from the name of this tribe: