'Phags pa is a groovy Brahmi derived script with some interesting origins. It is named for the Tibetan monk who invented it, 'Phags pa Blo gros rgyal mtshan (Christ, that's a mouthful). He was appointed as the national preceptor in 1264 by Kublai Khan and told to develop a script that could be shared across the languages of the empire: Chinese, Tibetan, Uyghur, and Mongolian. Among the nations themselves, there is no reference to 'Phags pa in their naming of the script, and records are somewhat sketchy.

Taking influence from Chinese and Mongolian in their vertical alignment, 'Phags pa was written vertically from left to right. It retains formations from Brahmi, but they are extremely blocky and lacking in any of the curves of the original script. Diacritics as well are differentiated, placed below the characters instead of above per standard Brahmi derivatives. Like other scripts of the same family, 'Phags pa is an alphasyllabary, or an abugida.

Despite its grand intentions, 'Phags pa was not actually used very much throughout the Mongolian empire. It was blocky, difficult to write, inefficient, and not properly tailored to write in so many different languages, not even to mention its complete disregard for the tones vital to Chinese languages! There are a few texts of it remaining, mostly written in old Mongolian, but besides that it remained mostly an ornamental script for Tibetan temples. An interesting theory, however, posits that King Seycong of Korea drew inspiration from 'Phags pa in constructing his own alphabet for the Korean language, hangul. The similarities in shape are distinctive, as well as the alignment of syllables in discrete blocks, however his script got rid of all the clumsiness and ambiguity of 'Phags pa, using it merely as a visual base for his own linguistically precise and scientific development.

Information sourced from Daniels, Peter T. Bright, William. The World's Writing Systems. Oxford: Oxford University Press, 1996.