1873 or 1879? Salford Red Devils’ true foundation year

This year marks 150 years since Salford Red Devils were formed, and it’s great to see the club is actively promoting this landmark. However, back in October 1979, Salford played host to Widnes in what was dubbed Salford’s centenary match. This clearly points to a foundation year of 1879. So, when was the club formed: 1873 or 1879?