Biography
Mr. Holme-Sumner’s mother was Margaret Joan Harvey, daughter of James and Agnes Harvey (nee Dunsmuir). He was therefore a great-grandson of Robert and Joan Dunsmuir. After the breakdown of his first marriage in Britain, Holme-Sumner resigned his commission in the British Army and moved to California where he changed his name to Pat Somerset and became a motion-picture actor, and eventually, a Charter Member and officer of the Screen Actors Guild.
Here is a photograph of Edward Arnold, Ronald Reagan, and Pat Somerset, officers of the Screen Actors Guild during talks about a 1947 film strike in California:
https://digital.library.ucla.edu/catalog/ark:/21198/zz0002t3f3 (last accessed July 24, 2022)