A hidden corner of British history, a savage mutiny by thousands of soldiers in World War I, has been uncovered by two writers here.

"The Monocled Mutineer" by William Allison and John Fairley penetrates a heavy veil of secrecy that the British high command has drawn over the events at Etaples for 60 years.

After six days of riots and killings in September, 1917, according to the book, the soldiers succeeded in ending a brutal training regiment at the Etaples camp and won the freedom to sample the limited joys of the small French town.

The book's title refers to Pvt. Percy Toplis, confidence man, racketeer and perennial deserter who frequently sported a gold-rimmed monocle when he posed as an officer.Toplis led a column of fellow deserters into the Etaples drama, the account says, and played a central role in winning the mutineers' demands.

Under the 75-year rule that classifies sensitive documents in Britain, the military had hoped the Etaples story could be suppressed until 1992. But Allison came across a memoir of the secret service agent who hunted down and briefly captured Toplis. This whetted Allison's appetite and, with Fairley, they traced some of the survivors of the mutiny through newspaper ads.

The only official document they could find, Allison said in a telephone interview, was the bowdlerized war diary of Brig. Gen. Andrew Thomson, commandant of the Etaples camp.

The tale pieced together by Allison and Fairley has a familiar ring for almost any army veteran. Etaples, a few miles east of the resort of Le Touquet, was the British army's biggest replacement depot. Hundreds of thousands passed through it on their way to the front.

Thomson, who had once been rebuked for lax discipline, put the replacements -- some of them combat veterans -- through a merciless grind. They were forced to train in the "bull ring" at the hands of brutal, rear echelon drill instructors. These were the "Yellow Canaries," so named because of their arm bands. For small infractions of discipline, the red-capped military police tied men by their wrists to a fence and left them in the open all day. The town and its two brothels were reserved for officers.

Eleven days before the great and futile offensive against Passchendaele-Ypres or "Wipers" to Americans -- a Scots corporal greeted a girl soldier he knew from Aberdeen. An MP moved in, ordered the corporal to button his tunic and march on. The pair fought and the MP shot the corporal dead.

That did it, Hundreds of Scotch, australian, New Zealand and English soldiers rioted, stormed a bridge into town and went hunting Red Caps and Yellow Canaries. At least six and possibly a score were beaten to death.

From the woods came the monocled Toplis, a stripling of 20 who had first been beaten by the law for swindling at the age of 11. He led a band of deserters who had learned that the best place to gain food and shelter undetected is around an army base with a floating population.

Toplis' band freed 50 prisoners from the stockade and surrounded Thomson. They demanded that he end the Bull Ring sessions, send away the MPs and give the camp's inmates freedom to visit Etaples.

At British army headquarters, Field Marshal Douglas Haig was baffled and enraged. His big push was to start in a matter of days. He feared his army would be paralyzed like the French forces, which had suffered massive mutinies a few months before. Haig responded in classic fashion. He demanded a blackout on the Etaples events, ordered everyone to the front as quickly as possible and relieved Thomson.

Haig also demanded that the ring-leaders be found and at least three subsequent executions are traceable to the Etaples mutiny.

But Toplis eluded his pursuers for nearly three years. He even re-enlisted under his own name, organized a racket selling army gasoline to truckers and built up reputation as a womanizer. Depending on his mood, he dressed himself in a variety of uniforms, from colonel to sergeant-major.

When a cab driver who played a small part in the gas racket was murdered, Toplis was charged with the killing and the manhunt intensified. He was finally ambushed by police in 1920 in northern England and gunned down on the spot. The killing saved everyone the embarrassment of a public trial.

Allison, an executive here in a feature service for foreign magazines, estimates that about 25,000 of the 100,000 troops in Etaples at the time actually took part in the mutiny.