East front of Wentworth Woodhouse, Yorkshire, with arms and motto of Watson-Wentworth, Marquess of Rockingham, on the pediment. Heraldry and motto borrowed by Watson, Baron Manton, an unrelated family. By coincidence it became the marital home of Joyce Langdale (Countess FitzWilliam) the aunt of the 3rd Baron Manton, who gifted him her paternal inheritance of Houghton Hall in YorkshireArms of Watson of Rockingham Castle: Argent, on a chevron engrailed azure between three martlets sable as many crescents orHeraldic achievement of Watson, Baron Manton: Arms:Argent, on a chevron azure between four martlets three in-chief and one in base sable a crescent between two roses of the field; Crest: A gryphon passant sable in front of an oak tree proper; Supporters: On either side a gryphon per fesse azure and argent charged on the shoulder with a rose also argent. (Montague-Smith, P.W. (ed.), Debrett's Peerage, Baronetage, Knightage and Companionage,  Kelly's Directories Ltd, Kingston-upon-Thames, 1968, p.739). The arms were adopted in 1922 on the elevation to the peerage of Joseph Watson, 1st Baron Manton (d.1922) of Compton Verney, Warwickshire, a soap manufacturer from Leeds, Yorkshire. The arms are a reworking of the arms of the unrelated family of Watson-Wentworth, Marquess of Rockingham, of Rockingham Castle in  Northamptonshire and of Wentworth Woodhouse in Yorkshire (Argent, on a chevron engrailed azure between three martlets sable as many crescents or), with the addition of White Roses of York. The crest is a mixture of the oak tree from the arms of Watson of Saughton, Chief of Clan Watson, a Scottish family, to which he was also unrelated, and the crest of Wentworth, a griffin passant argent. 

By coincidence the 3rd Baron Manton's maternal aunt Joyce Langdale of Houghton Hall in Yorkshire, married William Wentworth-FitzWilliam, 10th Earl FitzWilliam, of Wentworth Woodhouse, built by his ancestor Thomas Watson-Wentworth, 1st Marquess of Rockingham (1693–1750), and vastly expanded by his son, the 2nd Marquess. With Wentworth Woodhouse being the largest private residence in England and the Earl's second seat of Milton Hall, Peterborough, being the largest house in Cambridgeshire, also at her disposal, she may have felt little need to retain Houghton for her own use, and she gave it to her nephew w:Rupert Watson, 3rd Baron Manton, grandson of the 1st Baron. The motto Mea Gloria Fides ("trust is my renown"), is also borrowed, from Watson-Wentworth, Marquess of Rockingham, and appears sculpted below the Watson arms on the pediment of Wentworth Woodhouse.
Own work, using File:WatsonMantonArms.svg by Lobsterthermidor (talk) 15:04, 29 January 2021 (UTC); File:Silver-Gold Griffin Supporter (Heraldry).svg by User:Sodacan; File:GriffinPassant svg element.svg by Lobsterthermidor (talk) 15:04, 29 January 2021 (UTC); oak tree from File:Blason ville fr Nersac 16.svg by User:Chatsam; mantling using File:Coat of Arms of John Quincy Adams.svg by User:Glasshouse "using elements by Sodacan"
Lobsterthermidor (talk) 15:04, 29 January 2021 (UTC)