It’s the first Monday in May: Welcome to Met Gala mania.

With a livestream available when the evening gets underway, the world’s most fashionable fundraiser takes on one of the world’s most prolific — and controversial — designers, the late Karl Lagerfeld, as the starry party’s theme.

So how would the man of the hour, who died in 2019, feel about all the hullabaloo? Lagerfeld was a student of history, to be sure, but his eyes were forever on the future.

“Karl never wanted to have a retrospective when he was alive. He felt that it was funereal. He made the point that (Cristóbal) Balenciaga and (Coco) Chanel never had them when they were alive,” said William Middleton, who wrote the biography “Paradise Now: The Extraordinary Life of Karl Lagerfeld.”

So what about now?

“He believed very much in fashion history, so he’s a part of fashion history now. I don’t think he would have had a problem with it,” Middleton surmised.