Charles Dillon-Lee, 12th Viscount Dillon, KP, PC (Ire) (1745–1813) conformed to the established religion in 1767 and inherited Ditchley in England from his mother.

In January 1766 Pope Clement XIII ended the Catholic Church's support for the Jacobites and recognised the Hanoverian Dynasty as the rightful rulers of England.

[7] In 1776 Charles changed his surname from Dillon to Dillon-Lee and quartered his arms accordingly to comply with the will of his maternal uncle George Lee, 3rd Earl of Lichfield.

In that same year, his mother inherited the Lichfield estate at the death of her uncle the fourth Earl, who died childless.

Charles and Henrietta Maria had two children: On 4 November 1776 Robert Lee, 4th Earl of Lichfield, died and his earldom became extinct.

[22] In 1802 Lord Dillon sold the manor of Quarendon, where the seat of the Lee family had once stood, to James Du Pré of Wilton Park.

In 1806 Lord Dillon raised a regiment, namely the 101st Regular, recruited from the inhabitants of his Irish lands and surrounding areas near Loughglinn, County Roscommon.

[23][24] Despite his conversion, he was buried in the Dillon Family Vault in the Cemetery at the Augustinian Friary, Ballyhaunis, County Mayo, Ireland.