Who came up with the idea of making clothes for feet (socks)?

The person who actually invented socks is not known because they have been around for so long.
The earliest socks were made by tieing animal skins around the feet and ankles.  In the 8th century, BC socks were made from animal hair and worn by ancient Greeks.  In the 5th century, AD socks were worn by Holy people, in Europe as a symbol of purity.  
Later (about 400 years) socks were worn, by nobles, as a symbol of wealth.