From GFHS Marriage Index:
29 September 1801 John GRIFFITHS married Margaret KNIGHT by Banns at Gloucester St Mary de Crypt.

1851 Census entry for John:
Piece Folio SchNo Town Surname Forename Relatn Marr Age Occupation County Place
1959 0095 022 Ruardean Woodside KNIGHT John HD W 53 Coal Miner GLS Ruardean
1959 0095 022 Ruardean Woodside GRIFFITHS John LG W 64 Coal Miner GLS Ruardean
1959 0095 022 Ruardean Woodside PULLEN William LG U 47 Labourer GLS Redmarley

From GFHS Burial Index:
Date: 4 DEC 1850
First Name: MARGARET
Surname: GRIFFITHS
Age: 71
Burial Register: RUARDEAN 1847-1864
Place of Abode: RUARDEAN

Date: 26 JAN 1852
First Name: JOHN
Surname: GRIFFITHS
Age: 64
Burial Register: RUARDEAN 1847-1864
Place of Abode: WOODSIDE

Best wishes
Mike