Several 8-bit character sets (encodings) were designed for binary representation of common Western European languages (Italian, Spanish, Portuguese, French, German, Dutch, English, Danish, Swedish, Norwegian, and Icelandic), which use the Latin alphabet, a few additional letters and ones with precomposed diacritics, some punctuation, and various symbols (including some Greek letters).
The earlier seven-bit U.S. American Standard Code for Information Interchange ('ASCII') encoding has characters sufficient to properly represent only a few languages such as English, Latin, Malay and Swahili.
In the early days most of these were system specific, but gradually the ISO/IEC 8859 standards emerged to provide some cross-platform similarity to enable information interchange.
However, as Windows did not support the UTF-8 method of encoding Unicode (preferring UTF-16), many applications continued to be restricted to these legacy character sets.
All of these issues have been resolved as operating systems have been upgraded to support Unicode as standard, which encodes the euro sign at U+20AC (decimal 8364).