There are two saints who share this name. Saint Louis of Toulouse was born in 1274 and died in 1297, the year in which he was canonised. His attributes are a crown and sceptre. He was a Franciscan, reluctantly elevated to a bishopric, and a member of the powerful Angevin family which ruled much of the south of France and the kingdom of Naples.
The other Saint Louis is Louis IX, King of France (1214 - 1270). This saint is famed for his crusades and gathering of relics from the Holy Land. He is the patron saint of Paris and his attributes are a crown of thorns and nails from the cross.