how to "read" the context of a "character"

Gospel of Mark, Book of Durrow

biblical manuscripts can be divided into four groupings:

1- papyri,
2- uncials,
3- minuscules, and
4- lectionaries.

1- is based on the physical material (papyrus) used in the manuscripts. 

2, 3- two divisions are based on the script: uncial (majuscule) and minuscule. 

4- is based on content: lectionary (comes from list of "lections" for reading in a divine service).

Most papyrus manuscripts and lectionaries before the year 1000 are written in uncial script (uncial means "majuscule").

let's take a look at the "N" majuscule above in the Book of Durrow:

we have: base line (where all letters sit), mast (embroidered here), ascender (the portion of the minuscule letter that extends above meanline of a font), descender (the portion of the letter below the base line), and cap height.

observe, there is no separation between the letters, no punctuation (european languages and syntaxes are still evolving),

this typeface is known as scripto continua. 

take a look at this beauty, which was read based on knowledge of language "context" based on whether you have one, two, or three "minims."

if you're into typeface esoterics, click here.  

 Virgil's Georgics, made with capitalis quadrata