The first creation came on 19 March 1719 (as Baroness Glastonbury), as a life peerage and as a subsidiary title for Ehrengard Melusine von der Schulenburg, Duchess of Kendal and Munster, mistress of George I. The second creation came on 29 October 1797 when the politician James Grenville was made Baron Glastonbury, of Butleigh in the County of Somerset, with remainder, in default of male issue of his own, to his younger brother General Richard Grenville and the heirs male of his body.
The first creation was on 19 March 1719 (as Baroness Glastonbury), as a life peerage and as a subsidiary title for Ehrengard Melusine von der Schulenburg, Duchess of Kendal and Munster, mistress of George I. The second creation was on 29 October 1797 when the politician James Grenville was made Baron Glastonbury, of Butleigh in the County of Somerset, with remainder, in default of male issue of his own, to his younger brother General Richard Grenville and the heirs male of his body.