Indo-European and Uralic languages dominate present-day Europe, but both families are newcomers which replaced most of the indigenous languages step by step from the Bronze Age onwards. The encounter between indigenous and instrusive cultures, however, was most certainly not the only interaction that took place. By the time of arrival in Europe, the Indo-European and Uralic populations had already broken up and constituted a patchwork of languages and cultures that continued to converge and exchange. Whether contacts were connected to war or trade or exchange of inventions is revealed by the character of the loanwords in each individual case – and the shape of the loanwords reveal the time depth and the direction of borrowing. Traditionally, scholars have thought that basically all loanwords between Indo-European and Uralic languages went in one direction – from the former to the latter. Such an asymmetry is supposed to reflect a past relationship between two peoples where one had the upper hand, technically and politically, at the time of borrowing. In this dissertation it is shown that cultures of the Northeast played a surprisingly important role in the shaping of our continent from prehistoric to Medieval times. The Indo-European tribes, shortly after their migrations into Europe, came to form part of new cultural communities, influenced by Uralic populations from the North. This had a significant impact on specific parts of the vocabulary, notably terms for religion and warfare. Many terms for tools, animals and fruits can be shown to derive from Fennic and other languages of the Northeast. Even our word for ‘half ’, Danish halv, can be shown to derive from an old trading term meaning ‘reduced, cheap (of prices)’.