Edward King, a conservative Democrat who defeated Michael Dukakis for the Democratic nomination for governor on a pro-business, tax-cutting platform in 1978, then lost a rematch four years later, died Monday after a fall. He was 81.

Behind the slogan “Make it in Massachusetts,” King mounted a successful pro-business challenge to incumbent Dukakis, winning a bitter campaign by more than 100,000 votes in the 1978 Democratic primary.

“We were competitors, we were rivals, but he was someone who worked at his job very, very hard,” said Mr. Dukakis. “He wasn’t interested in going to Mexico or Canada. He worked at his job.”

King beat Republican Francis W. Hatch in the general election, then as governor, froze property taxes, reduced state spending on social programs, and undertook a variety of efforts to encourage business and agriculture.

King took a tough stance on crime, introducing mandatory minimum sentences. He succeeded in reinstating the death penalty after voters approved a 1982 constitutional amendment. But two years later, the state’s highest court ruled part of the law unconstitutional.

His stand on capital punishment prompted President Reagan to call King his “favorite Democratic governor.”

Reagan’s comment played a part in mobilizing more liberal Democrats to defeat King at the party’s 1982 convention, where he lost to Mr. Dukakis.

During his first visit to the Statehouse in nearly eight years in 1990 at the official unveiling of his portrait, King continued to torment Mr. Dukakis, calling him “arrogant” and “incompetent” and his second term “disastrous.”

King’s administration was also rife with charges of corruption, cronyism and incompetence. High-level appointees resigned for falsifying academic credentials and for ties to organized crime, while lower-level appointments went to relatives and others with strong personal ties to the governor.

King switched to the GOP in 1985, saying that the Democratic Party was controlled by liberals. “The truth is simply that the Democratic Party has ceased to be the party of the sensible center and has become a party dominated by professional liberals,” he said.

King considered running for governor as a Republican in 1985, but explained his decision not to run by saying his wife, while supporting his candidacy, would miss spending winters in Florida.

King sued The Boston Globe in 1982, claiming the newspaper libeled him in three editorial cartoons, an editorial and three political columns. A jury ruled against King in 1988.

King was born in Chelsea, Mass., and graduated from Boston College with a degree in business. He played three seasons of professional football as a lineman for the Buffalo Bills of the All-American Football Conference and the NFL’s Baltimore Colts, before working as an accountant in Boston.

His three years in professional sports helped him develop a lifetime of staying in top physical shape.

As executive director of the Massachusetts Port Authority in the 1970s, he oversaw the expansion of Logan International Airport.