Germany’s president is leading commemorations Thursday marking the 75th anniversary of Dresden’s bombing by allied forces at the end of World War II, an event that has become a test for the way the country handles its Nazi past.

Historians say up to 25,000 people perished during the three-day bombardment from Feb. 13-15, 1945, by American and British planes.

That is comparable to the death toll in other large German cities. But the man-made firestorm, vividly captured by American author Kurt Vonnegut in his book “Slaughterhouse Five,” and the destruction of large parts of the baroque city have become a rallying point for those seeking to portray Germans as victims in the war.

The myth that as many as half a million civilians were killed in the bombing has been promoted by far-right activists for decades. Most recently their case has been taken up by members of the nationalist Alternative for Germany party, which has grown into a significant force in German politics since its founding seven years ago.

The party, which goes by the German acronym AfD, has moved steadily to the right over the years. Bjoern Hoecke, a regional AfD leader who once called for a “180-degree turn” in the way Germany commemorates its past, was once considered a fringe figure but now represents the party’s core.

AfD’s co-chairman, Tino Chrupalla, recently stated that the bombing of Dresden cost “about 100,000 lives.” While such claims are dismissed by experts and condemned as revisionism by centrist parties, they reflect Alternative for Germany’s tactic of gaining attention by breaking taboos.

Last week, the party threw German politics into turmoil by unexpectedly backing a centrist candidate as governor in Thuringia state. The fumbled reaction to the situation by two other parties — including Chancellor Angela Merkel’s center-right Christian Democrats — triggered widespread outrage and numerous resignations, including that of Merkel’s heir apparent.

Marco Wanderwitz, a Christian Democratic lawmaker, said it was necessary to strike a balance in the way that Germany’s position in World War II is considered.

“The constant downplaying of Germany’s guilt, that’s a problem. This needs to be pointed out at every opportunity,” he said.

At same time, Germans need to find ways to talk about their citizens’ suffering in WWII, Wanderwitz added.

German President Frank-Walter Steinmeier and the Duke of Kent, a cousin of Britain’s Queen Elizabeth II, will join thousands of Dresdeners late Thursday to form a human chain in a gesture of reconciliation and to commemorate the victims of Nazi atrocities and mass bombings by all sides during World War II.