Slingsby Bethel was son of Sir Walter Bethel, knight, by Mary, daughter of Sir Henry Slingsby of Scriven, in Yorkshire, and sister to Sir Henry Slingsby, a steady loyalist, who was condemned by Cromwell's high court of justice, and beheaded on Towerhill in 1655. Bethel was early attached to the fanatical interest, both by religious and political tenets; he was even a member of the Committee of Safety. But he was a staunch republican, and no friend to the Protector; being, it is believed, the author of that famous treatise, entitled "The World's Mistake in Oliver Cromwell." He was elected sheriff, with Cornish, on Midsummer-day 1680, and the choice was, in many respects, disadvantageous to the popular party. In the first place, they were both Independents; and, before taking upon them their offices, they conformed, and took the sacrament according to the church of England's ritual. It was believed, that nothing but the necessity of qualifying themselves to serve their party in this office, could have prevailed on them to have done so, and this gave advantages against their whole party. Besides, Cornish was a downright, plain-spoken republican, and Bethel had expressed himself very bluntly in justification of the execution of Charles I.; and was, therefore, obnoxious to every slur which the royalists could bring against him, as ill-disposed to monarchy. Further still, Bethel's extreme and sordid meanness gave great disgust to the citizens, who were accustomed to consider the exercise of a splendid and ostentatious hospitality as the principal part of a sheriff's duty. He kept no table, lived in a chop-house, and, long afterwards, whoever neglected to entertain during his shrievalty, was said to "Bethel the city." Bethel is mentioned among the subjects of deprecation in "The Loyal Litany:"
From serving great Charles, as his father before;
And disinheriting York, without why or wherefore;
And from such as Absalom has been, or more;
Libera nos, &c.
From Vulcan's treasons, late forged by the fan;
From starving of mice to be parliament-man;
From his copper face, that out-face all things can;
Libera nos, &c.