Greeks have a long tradition of valuing and investing in "paideia" (education), which was upheld as one of the highest societal values in the Greek and Hellenistic world. The first European institution described as a university was founded in fifth-century Constantinople and continued operating in various incarnations until the city's fall to the Ottomans in 1453. The University of Constantinople was Christian Europe's first secular institution of higher learning, and by some measures was the world's first university.