The geography of population change in Europe has altered markedly in recent decades, with some remarkable switches in the location of the areas of fastest growth between the 1950s and the 1970s and with a rather general decline in the scale of geographical variations in growth rates since then. The dramatic declines in fertility and rates of natural increase in southern Europe (see Ch. 2) have played a major role in these trends, as has the long-established tendency towards convergence in mortality rates across Europe (see Ch. 5). Nevertheless, at the regional level it is the migration component that has been primarily responsible for the developments in population distribution.