The croissant's curve comes from an Austrian legend, not a French recipe
France's most famous pastry was not invented in France, and the crescent shape that names it rests on a story that cannot be confirmed.
The croissant is one of the symbols people reach for when they describe France, along with the Eiffel Tower and the beret. Yet it did not begin in France, and the curve that gives the pastry its name comes from a story rather than a recipe. The shape is a legend, and the legend is Austrian.
A crescent roll from Vienna
Long before anyone in Paris was folding butter into dough, bakers in Austria were making a crescent-shaped roll called the kipferl. At a glance the family resemblance is obvious: both are curved like a moon. The two are not the same thing, though. A kipferl tends to be denser, and can even be a kind of cookie, while a croissant is light and flaky.
That is where the trail of the shape leads, and it does not pass through a French kitchen.
The siege of 1683 and a flag in the sky
The best-known explanation for the curve comes from a battle. According to the legend, the kipferl was invented in 1683, when Vienna was besieged by Ottoman forces for two months. The city was freed when Christian forces of the Holy Roman Empire and the Polish-Lithuanian Commonwealth met the Ottoman army in battle.
To celebrate, Viennese bakers were said to have made a pastry shaped like a crescent, copying the moon on the Ottoman flag. It is a tidy story about food and victory. It also has a problem: the kipferl had already been popular in Austria for centuries by 1683. The real reason bakers chose that shape has been lost, and the siege story does not explain how the pastry reached France in the first place.
Marie Antoinette and the Versailles story
A second legend gives the croissant a royal escort into France. Marie Antoinette, the Austrian-born queen of France, was said to be homesick for Vienna and its treats, and to have introduced the kipferl to the court at Versailles, from where it spread among the French elite. There is nothing to back this up. It belongs with the other myths attached to the queen, who never said "let them eat cake".
What the record does show is more ordinary. Viennese pastries did not become popular in France until the mid-19th century, when Austrian bakers came to Paris, a city already well known for its food. One of them may have been August Zang, an Austrian soldier turned entrepreneur who opened a bakery called the Boulangerie Viennoise in the 1830s.
Why the straight ones are the buttery ones
Once the French took to the kipferl, they changed it. They built it from layers of buttery puffed pastry and gave it a new name: croissant, which means crescent. So the pastry is French in its modern form, with strong Austrian ancestry behind it.
The meaning of the shape then shifted again. As baking techniques developed, margarine or oil began to be used alongside butter. To tell the two apart, French bakeries now sell the margarine version in the traditional crescent shape, while the all-butter version is straightened. The curve that started as a legend about a flag now works as a label on a shelf: bent for margarine, straight for butter.