Thank God for Wikipedia [0] because this article says absolutely nothing about the actual invention of the script, except to credit it to the wrong people - the script was indeed named after St Cyrill but he and his brother Methodius invented a completely different script, from which a few characters were later taken and combined with Greek letters to make what eventually became modern Cyrillic. The real history is much more interesting than TFA!
[0] https://en.m.wikipedia.org/wiki/Cyrillic_script