After all, Lonely Planet, which was based by Tony Wheeler along with his spouse, Maureen, was itself named by mistake. Mr. Wheeler thought he was adopting the identify from the lyrics to “Space Captain,” sung by Joe Cocker and written by Matthew Moore — till his spouse corrected him. (The precise line is “Once while traveling across the sky, this lovely planet caught my eye.”)

A 1986 article by Nicholas Kristof in The New York Times anointed Mr. Crowther “the patron saint of travelers in the third world,” though Mr. Kristof acknowledged that even saints aren’t good. He talked about a jungle hike in North Borneo that had been included in “Southeast Asia on a Shoestring” on the suggestion of an earlier reader.

“Then, a couple of years later,” Mr. Kristof wrote, “a man came into Mr. Wheeler’s office and said: ‘You know that hike that you said would take a day and a half? It took me six weeks. Halfway through I was cursing your name, but later I realized it was the greatest adventure I’d ever had.’”

Not each traveler learn Lonely Planet’s guides for pleasure. After Ethiopian rebels used the guidebook’s maps of Addis Ababa, the nation’s capital, to seize it from the dictator Mengistu Haile Mariam in 1991, Mr. Wheeler marveled, “As far as I know it’s the only time we’ve directly helped to overthrow a government.”

Mr. Crowther’s uncompromising candor was not at all times welcome. He and his guidebook (“along with ‘Lady Chatterley’s Lover’ and a select list of other highly subversive titles,” Mr. Wheeler wrote) have been banned from Malawi after he gently badmouthed the nation’s autocratic president, Dr. Hastings Banda, in passing.

Declaring that Mr. Crowther “had an incalculable impact on a unique generation of travelers,” Richard Everist, a former writer of Lonely Planet, described him as “a true explorer and adventurer who went beyond boundaries and borders” and “defined Lonely Planet’s ethos and style.”

Geoff Crowther was born on March 15, 1944, in Yorkshire, England, to George and Susie (Halstead) Crowther. His mother and father have been each cotton mill employees.