With its single spire, the Gothic Cathedral of Notre Dame, once the tallest building in Christendom, has dominated the skyline of the French city of Strasbourg for centuries. On Dec. 23, 2000, the marketplace beneath the cathedral was bustling with shoppers and tourists, and the scene was captured on video by a group of men believed to be Algerians who had traveled by car from Germany.

"This cathedral is God's enemy," an Arabic speaker said on the shaky 20-minute video, which also recorded jihad battle songs on the car's cassette player as the men allegedly planned a bomb attack on the marketplace. "Here we see the enemies of God as they stroll about. You will go to hell, God willing."

The video captured the group's final preparations to set off a bomb eight days later, during New Year's celebrations, and unleash what could have been one of Europe's deadliest terrorist attacks, according to German police and prosecutors.

An intercepted phone call between one of the men seeking more cash and the group's alleged leader, who was based in London, tipped British intelligence to the plot, according to a report by Italy's anti-terrorist police.

On Dec. 26, a special German police unit raided apartments the men had rented in Frankfurt. The police found a bomb-making laboratory and seized a detonation device, machine guns, rifles with long-distance sights, $14,000 in cash, fake passports made in Thailand and the homemade video.

On Tuesday, in one of the first major trials of a cell linked to Osama bin Laden's al Qaeda terrorist network, five men will go on trial in Frankfurt for planning the attack in Strasbourg. They are charged with planning to commit murder, planning to cause an explosion, membership in a terrorist organization, falsifying documents and various weapons offenses.

Four others, including the alleged leader of the operation, are in French custody, and the alleged mastermind, Abu Doha, an Algerian also known as Amar Makhlulif, is detained in Britain. The United States is seeking his extradition to face charges in a plot to bomb the Los Angeles airport at the turn of the millennium

The Frankfurt trial, projected to last as long as a year, could lay out in the greatest detail yet the genesis, growth and goals of an al Qaeda cell in Europe. It could also expose the interlocking network of crime, fanaticism and terror born in the Arab world and sharpened in the terrorist training camps of Afghanistan before nestling into cities across Europe.

In a measure of how shadowy that world is, prosecutors said they are certain of the identity of only one of the five men facing trial. But police also said they believe they have enough evidence from the raid and cooperating witnesses to establish that a plot existed across Europe to bomb the Strasbourg market.

Members of the Frankfurt group were veterans of bin Laden's training camps in Afghanistan; among the items German police seized was a pistol produced in Afghanistan, which one of the men brought back as a souvenir, German officials said.

The group also worked with Muslim extremists in Britain, Italy, France, Spain and Belgium, according to police reports and interviews with intelligence officials and prosecutors. On a continent where the public often perceives the al Qaeda threat as directed against the United States, the Frankfurt group is a clear reminder that Europe, too, is a target, according to police and intelligence officials.

The Frankfurt group was composed of at least 10 members spread across at least three countries, Britain, France and Germany, according to an internal Italian police report that was filed with a court in Milan and obtained by The Washington Post. The report explored links between the Frankfurt cell and a group in Milan.

All five men facing trial were in Afghanistan between 1998 and early 2000, according to prosecutors. They began to coalesce in Germany late in 2000.

In July of that year, Fouhad Sabour, a French citizen of Algerian extraction, moved to London after having spent time in Bosnia and Pakistan, according to the Italian documents. In October, he flew to Frankfurt. Sabour, who was convicted by a French court in absentia in 1999 for bombings in Paris in 1995, is the only one of the five on trial whose identity has been confirmed.

A month after Sabour arrived in Frankfurt, Lamine Maroni and Salim Boukari, the latter also known as Kamal, followed from Britain. They had booked return flights to Britain from Frankfurt for Jan. 4 last year.

According to the Italian documents, Maroni's fingerprints matched those of a man who had been living in Sheffield, England, and was convicted of robbery. Boukari also has a British police record and, when arrested, was found with a stolen British passport.

In Frankfurt, the British-based men met up with Samir Karimou, Aeurobui Beandalis and the operations leader, Mohamed Bensakhiria, alias Meliani, who had an extensive criminal record in Germany, including attempted purse snatching, assault and violation of German asylum laws. Germany had rejected asylum applications by both Karimou and Beandalis, but they remained in the country. German police say they believe Bensakhiria, Karimou and Beandalis financed themselves through credit card fraud and drug dealing.

In December 2000, using a single American Express card, the men purchased business suits and, in 48 separate purchases, acquired bomb-making chemicals at pharmacies, German officials said. They reportedly told pharmacists they urgently needed the chemicals for a hospital in Africa.

French intelligence first alerted the Germans to a possible plot. The French message "indicated Abu Doha as the leader of an [Islamist] network based in London and a certain 'Meliani' as another leading figure," according to the Italian documents. Abu Doha was under surveillance for his suspected role in the plot to bomb Los Angeles, according to European officials.

On Christmas Eve, British intelligence "intercepted a telephone conversation between Abu Doha in the United Kingdom . . . during which a certain Kamal . . . told his English interlocutor of a planned terrorist attack at around the end of the year, in which he himself was to take part," according to the Italian report. Kamal, believed to be Boukari, wanted more money from Abu Doha for the operation, according to Italian investigators.

Two days later the police arrested four of the five men who are going on trial; Karimou was arrested in Germany in April last year.

Meliani escaped, but in June he was arrested on a French warrant for terrorist charges in Alicante, Spain, where other militants were helping him disappear among the transient worker community.

"The Meliani commando was integrated in the al Qaeda structure, the operational wing of bin Laden's international terrorist network," the Spanish Interior Ministry said in a statement at the time of the arrest.

Following the Frankfurt operation, British police arrested 12 people, including Abu Doha, in February last year, but they were quickly released, apparently for lack of evidence; Abu Doha was rearrested after Sept. 11 following a U.S. extradition request.

In February, French police arrested three men near Paris on suspicion of providing logistical support to the Frankfurt plotters. The French newspaper Le Parisien reported that one of those arrested, Yacine Akhnouche, 27, told investigators that he had visited al Qaeda camps in Afghanistan three times and had met Zacarias Moussaoui, the only person facing federal charges in the United States related to the Sept. 11 attacks, and Richard C. Reid, the Briton charged with trying to detonate explosives in his shoes on a flight from Paris to Miami. Le Parisien also reported that Akhnouche is reported as saying he met Ahmed Ressam, the Algerian convicted in the Los Angeles bombing plot.

Among the bomb-making equipment found in the Frankfurt raid was the same kind of rare detonator Reid used, Le Parisien reported, quoting unidentified French counterintelligence officials. The detonator also has been linked to a French-Belgian cell planning an attack on the U.S. Embassy in Paris.

Special correspondent Erik Schelzig contributed to this report.