Analysis of information sources in references of the Wikipedia article "比薩餅歷史" in Chinese language version.
Cheese, the crowning ingredient, was not added until 1889, when the Royal Palace commissioned the Neapolitan pizzaiolo Raffaele Esposito to create a pizza in honor of the visiting Queen Margherita. Of the three contenders he created, the Queen strongly preferred a pie swathed in the colors of the Italian flag: red (tomato), green (basil), and white (mozzarella).
Cheese, the crowning ingredient, was not added until 1889, when the Royal Palace commissioned the Neapolitan pizzaiolo Raffaele Esposito to create a pizza in honor of the visiting Queen Margherita. Of the three contenders he created, the Queen strongly preferred a pie swathed in the colors of the Italian flag: red (tomato), green (basil), and white (mozzarella).