During the first half of the 19th century, many Germans looked forward to a unification of the German states; one issue was whether Catholic Austria would be a part. German nationalists believed that a united Germany would replace France as the world's dominant land power. This argument was aided by demographic changes: since the Middle Ages, France had had the largest population in Western Europe, but in the 19th century its population stagnated (a trend which continued until the second half of the 20th century), and the population of the German states overtook it and continued to rapidly increase.