. While there is no question about the fact that Korean and Japanese share a large number of structural as well as a substantial number of material parallels, the explanation of the linguistic and extralinguistic background of these parallels is still disputed. The present paper defends the view that the parallels were formed as a result of areal interaction under concretely identifiable historical and protohistorical conditions. An overall understanding of the underlying extralinguistic circumstances is a prerequisite for the correct interpretation of the linguistic and philological corpus upon which comparisons between the two languages are based. When correctly understood, the comparative material suggests that Korean and Japanese have undergone a process of convergence, followed by gradual divergence continuing up to the present day.