Rose Mattus, who died Tuesday at 90, was the financial brains behind the first national brand of premium ice cream, Häagen-Dazs.

Few brand names have evoked as much folklore and outright confusion as Häagen-Dazs, which is faux Danish, sort of. The packaging, a pint container with a map of Denmark on the lid, does nothing to discourage the impression that it is a European import, a notion reinforced by its premium price.

It was speculated that Frank Sinatra was the first to introduce it to America.

The truth is that the brand was invented in 1959 by a Russian immigrant, Reuben Mattus, at his kitchen table and manufactured at his family ice cream factory, Senator Frozen Products, in the Bronx.

While Reuben handled the marketing and devised the original Häagen-Dazs recipe — much richer and with less air than standard ice creams of the day — Rose handled the business end, learning to buy in bulk, organizing a sales force, and designing an early distribution network that included sending cases of ice cream cooled by dry ice to distant college towns via Greyhound bus.

Rose Vesel met Reuben Mattus when they were children, both Eastern European Jewish immigrants in Brooklyn. She went to work as a bookkeeper at the Senator plant in 1934 and within two years had married Reuben.

It was always a small business, and sometimes on summer afternoons the young couple would take a trunk-load of ice cream down to Coney Island and sell it on the beach. By the 1950s, the business was being squeezed by larger companies, and Reuben came up with Häagen-Dazs.

Many stories have been told about the origin of the brand, but in her self-published 2004 memoir, “The Emperor of Ice Cream: The True Story of Häagen-Dazs,” Rose wrote that the Mattuses picked Denmark because of that nation’s exemplary treatment of the Jews during World War II. The name itself came about because Reuben respected the Duncan Hines brand and spent some time riffing on the words in faux Danish.

Häagen-Dazs got off to a slow start in 1960, available at first in some Manhattan delis and a couple of dipping shops. Later, it became popular among New York University students. “We found an alternative market, one steeped in the marijuana culture of the sixties,” Rose Mattus wrote in her memoir. “Our early clients were a motley assortment of oddballs with long hair, fringe tastes, and decidedly eccentric business styles.”

It was viral marketing before the term was invented, accomplished by word of mouth and Greyhound bus. The company never advertised, yet by the early 1970s it was the only premium brand of ice cream that could claim national distribution.

In the mid-1970s, the Mattuses moved the plant to Woodbridge, N.J., and in 1983, they sold the business to Pillsbury.

The Mattuses were known for their Zionism; a high-tech training center in Herzliya, Israel, is named for them.

At her 90th birthday party last week, Rose’s grandchildren presented her with 90 reasons why they loved her, according to Ginette Friedman, a co-author of Mattus’s memoir.