Donald Trump explained the appeal in one sentence: "Versailles is not gold leaf - Versailles is the real deal." For Emmanuel Macron, that was precisely the point.

On Wednesday night, the French president threw open Louis XIV's palace to his U.S. counterpart for a private reception, show and dinner marking America's 250th birthday.

At a turbulent moment for the trans-Atlantic alliance, it could help Macron keep a personal channel open as the two navigate differences over Iran, Ukraine and tariffs.