Frank Beardsley, a widower whose happy, if harried, domestic life inspired a book and two movies after he and his second wife each adopted their combined 18 children, and then had two more together, died Dec. 11 at a hospital in Santa Rosa, Calif. He was 97. (Courtesy of Carmel Pine Cone)

Frank Beardsley, a widower whose happy, if harried, domestic life inspired a book and two movies after he and his second wife adopted each other’s children — there were 18 in all — and then had two more together, died Dec. 11 in Santa Rosa, Calif. He was 97.

His son Michael Beardsley confirmed the death, but the family did not disclose the cause.

Mr. Beardsley, a Navy chief warrant officer with a brood of 10, lost his first wife to undiagnosed diabetes in 1960. The next year, he married Helen North, a mother of eight whose husband died in a Navy plane crash. They welcomed each other’s children, who ranged in age from 6 months to 15 years, before raising the tally to 20. In all, there were 12 girls and eight boys.

At the time, the military newspaper Stars and Stripes reported that the Beardsleys had the “undisputed largest military family in the nation’s history.” Helen Beardsley’s book-length account of their home life, “Who Gets the Drumstick?” (1965), was made into two movies with the title “Yours, Mine and Ours.”

Hollywood took liberties with the Beardsleys’ courtship and marriage. Both comedies — a 1968 version starring Henry Fonda and Lucille Ball and a 2005 version with Dennis Quaid and Rene Russo — played up the children’s sitcom-worthy efforts to sabotage the potential nuptials.

In the Ball film, the mother’s prospective stepchildren mix her a cocktail so potent that it recalls the physical comedy of the “I Love Lucy” television episode when Ball gets drunk off an alcohol-laced medicine called Vitameatavegamin.

Helen Beardsley’s “Who Gets the Drumstick?,” in contrast, was a warmhearted human-interest tale that was first excerpted in Good Housekeeping magazine. It described the children embracing their new parents from the start and explained how the family managed to function. Their working philosophy boiled down to the motto of the “Three Musketeers” — “All for one, one for all” — but modified for a bigger troupe.

Mr. Beardsley once described the book as a love story but also a “Navy story.” The family, which lived in a specially renovated home in Carmel, Calif., that sprawled to eight bedrooms and five bathrooms, relied on military-style organization to keep up with workaday chores. There were assembly line teams to wash dishes and make school lunches.

Daughter Susie Pope told the Santa Rosa paper that her father bought children’s shoes in bulk when they went on sale at the Navy base stores. For each child, there was one pair for Catholic school, another pair for church and athletic shoes for the weekend.

Frank Beardsley was inexact when selecting shoe sizes, but it didn’t matter. “Someone would grow into them eventually,” she said.

The family was featured in advertisements for a local bakery, which in turn supplied them with a year’s worth of bread. According to Helen Beardsley’s book, the Navy listed the Beardsley home as a restaurant, allowing them to buy food at wholesale prices from a nearby military commissary.

Francis Louis Beardsley was born Sept. 11, 1915, in San Francisco and was the ninth of 12 children. He served in the Navy from 1936 to 1968, eventually working at the Naval Postgraduate School in Monterey, Calif.

His first wife was the former Frances Albrecht. Helen Beardsley died in 2000.

Mr. Beardsley later married Dorothy Cushman, who survives, along with 20 children and dozens of grandchildren and great-grandchildren.

Son Greg Beardsley once told the Monterey Herald that his parents emphasized humility after the initial movie publicity made their family known to millions of viewers.

“My parents,” he said, “always used to remind us, ‘You’re only 5 percent of the equation, so 5 percent of a celebrity isn’t too much to brag about.’ ”