Margaret Louise "Polly" Grubb (September 22, 1907 – November 17, 1963)[2] was the first wife of pulp fiction author and Scientology founder L. Ron Hubbard, to whom she was married between 1933 and 1947.

His family settled in Loudoun County, Virginia, in 1762 from Brandywine Hundred, Delaware, and was descendant of John Grubb, who originally came from Cornwall in 1677.

[7] On May 7, 1934, Grubb gave birth two months prematurely to L. Ronald Hubbard Jr. (died September 16, 1991, in Carson City, Nevada), while on a vacation with her husband at Encinitas, California.

Ron Jr. legally changed his name to Ronald Edward DeWolf in 1972,[8] and the new name is thusly reflected in the California Birth Index, 1905–1995.

They settled in the community of South Colby, Washington, where Hubbard established a "writing studio" from where he produced many of his pulp short stories and novels.

The marriage came under strain when Hubbard began spending increasingly long periods in New York in order to be nearer his publishers and fellow pulp writers.

According to Robert MacDonald Ford, a friend who later became a state representative, matters came to a head when she found hard evidence of her husband's philandering: It seems Ron had written letters to a couple of girls in New York and left them in the mail box to be picked up.

[6] Hubbard later said that she had "become involved with another man and when her service allotment ceased just before the war's end, sought to obtain and was refused a divorce.

Grubb filed for divorce in Port Orchard, Washington, on April 14, 1947, on the grounds of "desertion and non-support", since neither she nor her children were obtaining any support from her absent husband.

[14][15] In April 1951, Hollister filed for a divorce from Hubbard after he left for Cuba with their daughter Alexis Valerie, accusing him of "paranoid schizophrenia" and of subjecting her to "systematic torture".

I haven't asked for anything but with the money rolling in from "Dianetics" I had hoped to get enough for plastic surgery for Kay's birthmark – Please believe I do so want to help you get Alexis.

[16]Although she played a major part in Hubbard's life, Grubb is not mentioned in official Church of Scientology biographies.