A large number of manuscripts are covered with painted ornaments in the form of initial letters or of borders, of marginal and full page paintings; and some rolls of parchment consist entirely of paintings.
They are called illuminations or miniatures.
The most ancient examples of this art are on Egyptian papyri.
It was practised by the Greek artists of Alexandria.
The Syro-Mesopotamian School arose in the 5th century in the Christian convents of the East and its influence spread to Armenia.
The Mussulman schools of the 13th century excelled in geometric designs and the Persian painters attempted landscape and even the human face.
The 9th century is the golden age of Byzantine illumination which combines Hellenic and Oriental influences.
All the manuscrips of the Slavic countries belong to the Byzantine school and also show direct influence of the Orient.
In the West the earliest school was the Irish which excelled in decorative work.
The "Book of Kells" (7th century) is a famous example.
Irish monks brought the art to England and the Continent.
Under Charlemagne the art fiourished in the monasteries and a style of vigorous coloring and luxurious ornamentation was introduced.
In the 11th century there is the beginning of naturalism and anachronism.
More grace is shown in the treatment of figures.
In the 13th century studios of illuminators arose to supply the demand for manuscripts.
Works of profane literature were illuminated.
A new school in the 14th century introduced garlands copied from nature and scenes from life.
A transformation took place in 15th century through the influence of Flemish painters; real landscapes are used as backgrounds, figures are treated with fidelity to nature, and all details of furniture, clothing, etc., are portrayed.
The invention of printing and wood-engraving was fatal to the art of illumination.
New Catholic Dictionary