What does this have to do with art? Script is lettering; it is calligraphy, it is writing, they are symbols of communication; and obviously needed for manuscripts. They comprise the words written between the Illuminated Pages, and how history was passed down to us via scribes—by hand, before print—for religious and non-religious purposes. It was so important that pictures were painted depicting it. This is one of the arts of which Charlemagne had great influence over. It started in monasteries (new subject!). It is an art form and it is known as paleography.
This is a retouched picture, which means that it has been digitally altered from its original version. Modifications: cropped detail. The original can be viewed here: Minuscule_caroline.jpg. Modifications made by "Paj". Wikimedia Commons
From the fantastic Medieval Writing website, Drs. Dianne and John Tillotson write:
"The development of Caroline Minuscule, or Carolingian minuscule, was a reform which increased the uniformity, clarity and legibility of handwriting. It was evidently developed in the late 8th century scriptorium of Charlemagne, or in those of the monasteries under his patronage, in the course of his conscious efforts to revive the literate culture of Classical Rome."