The most obvious link between modern and ancient Greeks is their language, which has a documented tradition from at least the 14th century BC to the present day, albeit with a break during the Greek Dark Ages (lasting from the 11th to the 8th century BC). Scholars compare its continuity of tradition to Chinese alone. Since its inception, Hellenism was primarily a matter of common culture and the national continuity of the Greek world is a lot more certain than its demographic. Yet, Hellenism also embodied an ancestral dimension through aspects of Athenian literature that developed and influenced ideas of descent based on autochthony. During the later years of the Eastern Roman Empire, areas such as Ionia and Constantinople experienced a Hellenic revival in language, philosophy, and literature and on classical models of thought and scholarship. This revival provided a powerful impetus to the sense of cultural affinity with ancient Greece and its classical heritage. The cultural changes undergone by the Greeks are, despite a surviving common sense of ethnicity, undeniable. At the same time, the Greeks have retained their language and alphabet, certain values and cultural traditions, customs, a sense of religious and cultural difference and exclusion, (the word barbarian was used by 12th-century historian Anna Komnene to describe non-Greek speakers), a sense of Greek identity and common sense of ethnicity despite the global political and social changes of the past two millennia.