He was succeeded by his son, the second Earl, who married Lady Mary Tudor, daughter of Charles II by his mistress Moll Davis.

Despite having been stripped of his titles through the attainder, his only son John, titular 4th Earl of Derwentwater, continued to use them.

He was also a Jacobite but managed to escape to France after the 1715 rebellion, where he was secretary to Charles Edward Stuart ("Bonnie Prince Charlie").

In 1814, William Radclyffe (1770-1828) of Darley Hall, Worsborough, made claim to be the next legitimate heir to the title.

In 1816, it was discovered that Radclyffe, who had in 1803 been appointed as Rouge Croix Pursuivant, a member of the College of Arms, had used his position to alter entries in the Parish Register of Ravensfield to substantiate his false claim.

In the mid-19th Century the so-called "Mad" Countess of Derwentwater, a woman calling herself Amelia Mary Tudor Radcliffe, took possession of Dilston Castle and claimed that the titular 4th Earl John had not died at age 19, but had faked his own death and relocated to Germany to avoid Hanoverian agents.