The capitalis monumentalis is the kind of lettering developed in the Roman Empire between 600BC-400AD. It is undoubtedly the father of capital letters in fonts we use today.

This lettering was undoubtedly the most beautiful typeface the Romans developed, and it was used (as the name suggests) in monuments and buildings, and written on them with chisels. (The letters used when writing on other surfaces, such as wax, using stylus, were capitalis quadrata, decent enough for general purpose writing, and capitalis rustica, less intricate and good for hastier writing.)

The most important "innovation" in this writing was what is these days often called serif; it apparently helped to keep the resulting cracks in stone from spreading.

I already mentioned how beautiful the typeface was. The letters were stronger than in the greek fonts of the time, and their proportions were very carefully thought of. The whole thing was a very nice blend of aesthetics and consideration of the limitations of the medium and writing tools. Undoubtedly, the Romans understood the importance of careful font design.

One example of computerized version of the font is Adobe's Trajan.

(Noding my homework... a lot of information from the lecture, but the notes are in the web: