The whole 'claim to ancestral homeland' is complete bunk as far as I see it. Some extracts from European history:
Take UK. Originally it was inhabited by Celtic people, such as now live in Ireland, Wales and to some extent Scotland. Incidentally, most of Europe was inhabited by Celts, including modern-day France, large parts of Spain and Eastern Europe. Then Roman Empire (whose capital was in modern-day Italy) happened and Britain was romanised, with large number of people from elsewhere in the Empire settling there. Then, as the Empire declined, the Romans left Britain, shortly after that there was an invasion by Angles and Saxons, which were Germanic tribes. Many of Germanic tribes, incidentally, originally migrated from modern-day Scandinavia due to climate change and overpopulation. For a while Angles and Saxons controlled Britain, mixing with the locals, until there was an invasion from the North, by Vikings, who were obviously from Scandinavia, and from the South by the Normans (who were French but also descendants of Vikings).
In the meantime in the Eastern Europe the Celtic and other people were displaced by Slavs, coming in large numbers from the East. Hungary is an interesting case. Some Hungarian historians claim descent from Huns, who were originally believed to originate from modern-day Mongolia or perhaps western Siberia, but most historians agree actually descended from Magyars, who were originally nomadic people who mass migrated to what is modern-day Hungary (more or less) from somewhere west of the Ural mountains (in modern-day Russia).
I could go on and on but you get my point. People are driven from one place, due to war or environmental changes or other factors, are in turn driven out by other people and so on and so forth. History is dynamic like that. Now imagine all of the people in Europe and elsewhere in the world (because these kind of migrations weren't limited to Europe obviously) all decided to 'reclaim their ancestral home'. Hell, go back a few hundred thousand years and we all came from Africa. So maybe The Scramble for Africa and all the colonization was just Europeans reclaiming their ancestral homeland?