Centuries-long

This was part of a centuries-long program of cultural genocide that culminated in the physical genocide of the Holocaust.

Source: tatoeba (8910906)

All of the European nation-states, not just Nazi Germany, were participants in the centuries-long genocide that culminated in the Holocaust.

Source: tatoeba (8910911)

No city in the world has a more varied history and interest, and in none can better be traced the centuries-long line of steady progress from barbarism to civilisation.

Source: wiktionary

For he had not only handed in his resignation as Chief of Staff; he had gone a step further. He had left the Army, given up his title of general. He had done something that had scarcely ever happened during the centuries-long history of the Prussian Army.

Source: wiktionary