When “I” shrunk to a single letter, one little letter had to represent an important word, but it was too wimpy, graphically speaking, to carry the semantic burden, so the scribes made it bigger, which means taller, which means equivalent to a capital.”

Very nice resource.

A map of the wheel-ruts of modern English. Etymologies are not definitions; they're explanations of what our words meant and how they sounded 600 or 2,000 years ago.

Online English Learning