The South Pacific had a fascination for David McTaggart. He bought a boat, the Vega, and sailed from one evocative landfall to another. In 1972, at the age of 39, he heard that Don’t Make a Wave was protesting about French nuclear tests on the island of Mururoa. France had tested its first bombs in the Sahara desert, but in 1966 it had moved its nuclear test site to the more distant Mururoa, an uninhabited island that is part of French Polynesia.

Although Mururoa is remote, nuclear watchers were worried that the French tests were above ground, potentially polluting the atmosphere for many hundreds of miles beyond its shores. The United States had ended tests in the atmosphere in 1962, and the Soviet Union in 1963. Now here was France nine years later continuing to send poisonous mushrooms into the Pacific skies.

When the next test was reported to be imminent, he set out from Tahiti for Mururoa, about 960km (600 miles) away, in the 36ft Vega. The French had taken great trouble to clear the seas around Mururoa and tried to persuade Mr McTaggart to sail away. He declined. They postponed their test, then rammed the yacht. It was damaged but still seaworthy, and Mr McTaggart hobbled back to Tahiti.

Next year he returned to Mururoa. This time French commandos boarded the boat and beat him up. In 1974 Mr McTaggart won damages in a French court. The same year France ended atmospheric tests, instead exploding nuclear devices underground in Mururoa.

Mr McTaggart became a leading figure in the fraternity of the environmentalists. He took over Don’t Make a Wave, and renamed it Greenpeace. He worked to bring together, possibly, millions of environmentalists. Their weapon was publicity through exploits of Greenpeace’s front-line “soldiers”. Mr McTaggart would be first over the top.

He continued his war with the French over nuclear testing, again visiting Mururoa. The angry French retaliated in 1985 by blowing up a Greenpeace ship, Rainbow Warrior, in Auckland harbour, killing one person aboard. Greenpeace mourned the loss, but gained comfort from the worldwide condemnation of the French.

Mr McTaggart always sought to promote it as the brave struggling group. A newspaper picture of young idealists in rubber boats foiling whalers or climbing an oil rig to warn of pollution was what kept the public sympathetic.

In 1991 he gave up the chairmanship and bought a farm in Italy and produced olive oil: organic, of course. He occasionally returned to the fray, most recently in 1995, with yet another trip to Mururoa. He died in a car crash near his home in Umbria.

For a person who used publicity to further his cause, surprising not a lot is known about David McTaggart. He turned down requests for interviews. Little detail has emerged about his personal life. He had a son, but stories that he was married three times and had four daughters have not been confirmed. His speech was far from elegant, and much punctuated by expletives. No one who knew him can recall any stirring phrases. He would listen to a lieutenant’s plans for a new exploit and, if he approved, tell him to get on with it.