it is believed that the reason why mongolian script is vertical is so that it could easily be written on the neck of a horse, which horses were a very important part of mongolian culture. in the year 1208, genghis khan captured a uighur scribe named tatar-tonga and forced him to make the alphabet of his native language, the old uyghr alphabet, be used to write the mongolian language. it did not fit the mongolian language well, and it was difficult to learn even for native mongolian speakers.