The 5th century Christian art is a particular artistic phenomenon which takes an intermediate position between the Antiquity and the Middle Ages. First of all, it is characterized by the coexistence and unique combination of antique and Christian art elements. During the 5th century an active research and scrupulous selection of the new modes of artistic expression, usually associated with the Christian Byzantine and West European art, took place. The absolutely new symbolic language suitable for the expression of the Christian theological concepts formed by the beginning of the 6th century.
The creation of distinctive Christian artistic language was a long and gradual process. The artists could not change the normal and habitual for them ancient models, to find and adopt the new symbolic forms immediately.
This report focuses on one special technical device, which the ancient artists used to create a spatial effect, and which transformed into a symbolic form of the halo used to underline the spiritual power of the saints in the 5th century Christian mosaics. We shall demonstrate this process on certain examples.

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