Tragedy struck the Notre Dame Cathedral in Paris on Tuesday. Famously outspoken conservative historian Dominique Venner committed suicide in front of the altar of the church, causing a mass evacuation of the premises.

"It's unfortunate, it's dramatic, it's shocking," said Monsignor Patrick Jacquin, the cathedral's rector. "We did not know him, he was not a regular at the cathedral."

Around 1,500 people were ushered out of the cathedral after Venner shot himself in the head. Notre Dame is a national landmark that is visited by some 13 million people every year.

"We call for compassion," Interior Minister Manuel Valls said. "Notre Dame is the cathedral of Paris, one of the capital's -- and the country's -- most beautiful monuments, so we realize how symbolic this event truly is."

Venner appears to have committed the suicide in response to a recent move by French lawmakers to decriminalize same-sex marriage. He had this to say on his blog prior to his death.

"An infamous law...can always be repealed," Venner observed. "It will require new, spectacular and symbolic actions to rouse people from their complacency."

It is believed that this is the first time that anyone has committed suicide in front of the cathedral's altar, though some people have committed suicide by leaping from one of its two towers. Notre Dame is celebrating its 850th anniversary this year.

Venner fought in the French Army 50 years ago and has since been a vocal supporter of right-wing, conservative values. He was a long-time opponent of gay marriage, immigration and adoption.

"All respect to Dominique Venner whose final, eminently political act was to try to wake up the people of France," leader of the far-right Front National (FN) Marine Le Pen said on Twitter, adding later "it is in life and hope that France will renew and save itself."