Robert B. Parker, the best-selling mystery writer who created Spenser, a tough, glib Boston private detective who was the hero of nearly 40 novels, died Jan. 18 at his home in Cambridge, Mass. He was 77. The cause was a heart attack, said his agent of 37 years, Helen Brann.

Parker wrote more than 60 books all told, including Westerns and young-adult novels, but he churned out entertaining detective stories with a remarkable alacrity that made him one of the country’s most popular writers.

In recent years he had come up with two new protagonists: Jesse Stone, an alcoholic ex-ballplayer turned small-town chief of police, featured in nine novels written since 1997; and Sunny Randall, an unlucky-in-love, daughter-of-a-cop private eye created at the request of the actress Helen Hunt, who was hoping for a juicy movie role. No movie was made, but the first Sunny Randall novel, “Family Honor,” was published in 1999, and five more have followed.

It was Spenser, though — spelled “like the poet,” as the character was wont to point out (his first name was never revealed) — who was Parker’s signature creation. He appeared for the first time in 1973 in “The Godwulf Manuscript,” in which he is hired by a university to retrieve a stolen medieval document, an investigation that triggers a murder. The first pages of the book revealed much of what readers came to love about Spenser — his impatience with pomposity, his smart-alecky wit, his self-awareness and supreme self-confidence.

“Look, Dr. Forbes,” Spenser says to the long-winded college president who is hiring him. “I went to college once. I don’t wear my hat indoors. And if a clue comes along and bites me on the ankle, I grab it. I am not, however, an Oxford don. I am a private detective. Is there something you’d like me to detect, or are you just polishing up your elocution for next year’s commencement?”