Around the 5th century CE, Latin was written in all-caps without any spaces between words:
4th-century Codex Bobbiensis
During the Carolingian Rennaisance c. 9th century CE, Charlemagne and others oversaw many changes in written latin, including addition of spaces between words, punctuation, and capitalization at the start of sentences. All of these changes led to a much cleaner and more readable page:
Interestingly, this occurred contemporaneously in the Byzantine empire around the same time with Greek miniscule:
10th-century manuscript of Thucydides.
Seems like there was an overall trend to go from Majuscule to Minuscule typography as more and more people became literate and learned to handwrite with ligatures, and wanted others to be able to read their writings.
All the while, parchment was in short supply, so even miniscule needed to be condensed. Much was lost because the same parchment would be used and re-used multiple times.