THE CHRISTIAN REALMS 265Like the fifth and eighth, and the sixteenth to follow, the eleventh
century and early twelfth marked a period of profound change in the
peninsula, in which the ideology of the Reconquista was first born. But
there remains in Spanish history an essential continuity that tran-
scends such times of cataclysm and upheaval, born perhaps out of the
shared experience of the aspirations towards unity, and the resistance
to them, both deeply rooted in the past and in the geography of the
land, that remain as strong today as in the time of the Romans,
Visigoths and Umayyads.