History never recorded whether an Englishman named John Strong knew what he was starting when he sailed to New England in 1630, married a woman who also had survived the voyage--and fathered 18 children.

But John Strong's progeny--especially his 110 direct descendants who gathered in Washington for a family reunion this weekend--like to think the Massachusetts tanner would be pleased by the way the clan turned out 12 generations later.

"He's our inspiration, really, one of the big reasons why we gather year after year," Sidney Strong, 86, of Atwater, Minn., said yesterday. "We Strongs have a reverence for our ancestors. John Strong would've wanted us to remember our roots, don't you think?"

Twentieth-century Strongs--at least the 600 people in 46 states who are members of the Strong Family Association of America Inc.--are not content with mere reminiscing. They revel in their past, spinning tales of Samuel Strong's kidnaping by Indians in the early 1700s and of Revolutionary War hero Nathan Hale's mother--a Strong, naturally. They scamper up and down the family tree, whiling away hours on its most remote branches.

"It's like eating peanuts: You can't stop at just one," said Daniel C. Strong, a genial New York City policeman who has compiled a 6,000-card file on the Strongs since he was hooked on family lore 20 years ago.

"It's a lifelong hobby, a way of personalizing history," agreed B. Jean Strong, a District resident who works in the marketing division of Time-Life Books. "You can never be finished."

The Strong Association started the annual reunions in 1975 and this year used the National 4-H Center in Chevy Chase as headquarters for forays into Washington and lectures on such topics as "Genealogical Research Opportunities in the Baltimore-Washington-Annapolis Areas" and "Early Virginia Strongs."

Association President Jarvis A. Strong Jr., a retired Air Force colonel who lives in Reston, said the reunion rivaled the memorable 1982 visit to Boston's Dorchester neighborhood, which John Strong helped found. "Of course, we're here to compare notes on our genealogy research," Jarvis Strong said. "But there's something more.

"We enjoy getting together. It's a kissing-cousin-type thing." One distant cousin, according to the association's research, is Lady Diana, Princess of Wales.

At their banquet last night, the Strongs were scheduled to confer on her an honorary lifetime membership in the association.

Many of the Strongs, some of whom traveled from California and Oregon, said the highlight of this year's gathering was the three hours they spent yesterday at that nirvana of genealogy, the National Archives. "This is exactly like detective work," sighed Norma A. Harris, a retired bookkeeper from Fort Pierce, Fla. whose great-great grandmother was a Strong. Moving thoughtfully through the archives' microfilm room, Harris jotted notes on her official Strong family note pad. Its cover was emblazoned in gold with the family crest and motto: Tentanda Via Est, which translates, Jarvis Strong said, as "The Way Is To Be Tried."

The reunion's youngest Strong was Kelly Faye, the six-week-old daughter of Ray Strong, a Mississippian who recently moved to Springfield.

"I joined about a month ago," said Strong, who has researched his side of the family only to 1850. "I had no idea a group like this existed. But it's terrific."