Sharp s

ß began as a ligature in blackletter type, a long s joined to a tailed z, for the sz spelling of late medieval German. Its German name, Eszett, is simply the names of those two letters.

Switzerland and Liechtenstein stopped using it in the twentieth century and write ss instead, and the German spelling reform of 1996 reduced its use. For centuries it had no capital form. Unicode added ẞ in version 5.1 in 2008, and the Council for German Orthography accepted it as an official capital in 2017.