An illumination is an embellishment, or additional decoration that enhances the pages of a written manuscript page.
The term Illumination comes from the term Illuminate, or to fill with light. This effect is achieved with the application of gold leaf to the letters and images, which reflect light and appear to glow.
An illuminated letter was usually the first letter of a page or paragraph. It was always enlarged and in color with gold applied in areas, while the rest of the text remained black. The images used to enhance the letter include animals, plants, and mythological creatures. These images were modified to fit into or around the letter, or in some cases took the shape of the letter itself. Because the recording of historical events was such an important task, illuminations were ordered by Kings and religious leaders to be added to various pages in order to add interest and importance to their appearance.
The Egyptians were the first culture known to document events by use of Illuminated Manuscripts. One of the most famous being the Book Of The Dead, which dates back to 1310 B.C.
As written languages developed, various countries adopted the idea of illuminating their manuscripts and carried on the tradition for hundreds of years into the Medieval Europe and during the Middle Ages.
By the 7th Century, Illuminations became a highly respected art form. At this time some of the most beautiful and famous illuminations were being created in Ireland and England.
Drop caps are the contemporary version of the illuminated letter. They are characterized by having similar characteristics to illuminated letters, only usually done in a more modern approach.
The first letter of a paragraph that is enlarged to "drop" down two or more lines, as in the next paragraph. Drop caps are often seen at the beginning of novels, where the top of the first letter of the first word lines up with the top of the first sentence and drops down to the four or fifth sentence.