From
Wikipedia; most of these are quite fanciful (including Bl. Marco's role in the invention of cappuchino), but they make for good reading.
One legend is that the croissant was invented in Vienna, either in 1683 or in an earlier siege in 1529, to celebrate the defeat of the Turkish siege of the city, as a reference to the crescents on the Turkish flags. Although this version is supported by the fact that croissants in French Language are referred to as Viennoiserie and the French popular belief that Vienna born Marie Antoinette introduced the pastry to France in 1770, there is no evidence that croissants existed before the 19th century.
Another legend from Vienna has the first bagel as being a gift to King Jan Sobieski to commemorate the King's victory over the Turks that year. The baked-good was fashioned in the form of a stirrup, to commemorate the victorious charge by the Polish cavalry. The truth of this legend is very uncertain, as there is a reference in 1610 to a similar-sounding bread, which may or may not have been the bagel.
After the battle, the Austrians discovered many bags of coffee in the abandoned Turkish encampment. Using this captured stock, Franciszek Jerzy Kulczycki opened the third coffeehouse in Europe and the first in Vienna, where, according to legend, Kulczycki himself or Marco d'Aviano, the Capuchin friar and confidant of Leopold I, Holy Roman Emperor, added milk and honey to sweeten the bitter coffee, thereby inventing cappuccino.
For Blessed Marco d'Aviano, a Capuchin military chaplain, and the subject of a fair amount of controversy himself, see
here.