PARIS — On the eve of the new millennium, the Dutch journalist and historian Geert Mak traveled across Europe, crisscrossing the continent with the hope of answering the question “What it meant, that misty term, Europe.” His book, “In Europe: Travels Through the Twentieth Century” (Pantheon, 896 pages, $35), is the superb product of that year-long journey.

I spoke with Mr. Mak at a café by the Assemblée Nationale in Paris, where he described his newly translated project as “traveling through time through the continent.” In his peregrinations, Mr. Mak followed a route that mimicked the course of the 20th century, a chronological journey, part travelogue, part history book. This hybrid style led to the success of his earlier book, “My Father’s Century” (1999), an account of Mr. Mak’s family interwoven with the history of the Netherlands.

“In Europe” records the living memories of an impressive array of witnesses, from politicians to resistance fighters and partisans, to veterans of the Soviet and German armies. The stories he uncovers are unique and often terrible. We hear from Winrich Behr, for example, a former officer on the staff of Nazi Field Marshall Friedrich Paulus, who had the unenviable job of personally reporting the defeat at Stalingrad to Hitler. Paradoxically, it was when traveling in Europe’s hinterlands that the question of Europe came into focus for Mr. Mak. Looking through the eyes of those who live along Europe’s hazy margins, Mr. Mak discovers Western Europe as a kind of Other, distinctive for being “over there.”

And yet, when searching for Europe from within, Mr. Mak finds the connections between Europeans are less a matter of location than of shared experience. His view of Europe is an inclusive one, defined by the “strong common identity” in the lessons of the two world wars.

It is a broadly defined notion of the continent that bears directly on the question of European enlargement, and contradicts those who would argue, as in the case of Turkish accession, that the European project is defined by shared values. Turkey may not be culturally western, but its history is indisputably interlocked with Europe and World War I, which by Mr. Mak’s measure makes it European. But Europeans trying to come to terms with the diversity of postwar immigrants, many of whom share no experience of the European wars, might find Mr. Mak’s approach raises more questions than it answers. Diversity itself, Mr. Mak argues, is the hallmark of European civilization — and the tragedy of recent history unites it.

As “In Europe” makes starkly clear, the legacy of the terrible first 45 years of the 20th century still stalks the continent. To this day, there are still fields in Europe that extrude the detritus of war – bones and munitions – the flashbacks of a scarred land.

In the Baltics, Mr. Mak finds a hotbed of holocaust denial. The percentage of Latvian Jews who survived is the lowest in all of Europe: 1.9%. “In his official report,” Mr. Mak writes, one German officer characterized the [Lithuanian] farmers’ hatred of the Jews as ‘monstrous.’ They had ‘already done a great deal of the dirty work’ before the Germans could intervene.

In the capital, Riga, the director of the Jewish museum tells Mr. Mak, “If a German soldier had not happened to take a couple of pictures, the massacre in the dunes would never have [officially] happened.”

Mr. Mak is a skilled distiller of archival evidence, but his firsthand witnesses deliver us even more harrowingly into the past. A survivor of the bombardment of Guernica describes her experience emerging from the bomb shelter:

Finally a man came in and said ‘You can all go out now. But Guernica is gone. There is no Guernica any more. We went outside and you saw a hand lying here, a foot lying there, a head lying over there. And the whole city was red. Everything was just silent and red, as red as this.’ He points to a coke can.

Despite Mr. Mak’s efforts to re connect his readers with the past one has the eerie experience, in reading his book, of rediscovering the past century, even while the towns and villages he visits are busily forgetting it. Many Europeans seem incurious, and recognize their continent only vaguely In Barcelona, for example, Mak describes Das rollende Hotel, a bus packed with Germans who sleep stacked in “little berths like sausage rolls in a vending machine. … It is not that bad, an older man tells me. ‘It’s sort of like a ship’s cabin.'” Nearby, Mr. Mak finds the ruins of the village where the Abraham Lincoln Battalion fought General Franco’s tanks. The site was recently used as a backdrop for TV commercials for the Dutch Army. Eventually, much of history serves as an exotic prop.

Mr. Mak believes such forgetting is the blessing and the curse of the exceptional prosperity that followed World War II. Indeed, the very structure of “In Europe” is representative of this: Mr. Mak describes the 1946 Nuremburg trial two-thirds through the book. Thereafter, it is as if we are treated to highlight films of only the championship seasons — ’56, ’68, ’89. Likewise, today’s affluent Europeans are living amidst one of the most comprehensive idealistic experiments in the continent since the French Revolution. But, as Mr. Mak points out, it is hard to notice that it’s happening. As he remarked to me, “for the young people of Europe today, peace was like water from the tap: just normal.”

Mr. Treneer, a writer living in Paris, last wrote for these pages the novel “Vie Française,” by Jean-Paul Dubois.