The name Siegen comes from the possibly Celtic river name Sieg. It is, however, unclear whether there is any relation between this name and the Celtic-Germanic Sicambri (Ger. "Sugambrer") people, who in pre-Christian times lived in parts of North Rhine-Westphalia. The first documentary mention of the place called "Sigena" dates from 1079. The city's history is markedly shaped by mining, which locally began as far back as La Tène times. Bearing witness to this longtime industry are the many mines that can be found within city limits.