Arabs were the ones who introduced spinach to the Mediterranean world, where the hot, dry weather demanded special techniques of irrigation(2). Muslims brought it to Sicily in 827(1), and Spain cultivated it by the 1000s. Italy(2), Germany, England, and France would all come across some of the various forms of spinach or other by the close of the Middle Ages. It became popular in northwestern Europe as a spring veggie as at the time, there really weren't other spring veggies available(1). Jews of the Mediterranean caught on to it to where they employed such "dishes such as shpongous, a savory baked dish of sheep's cheese and spinach that was customary as a dairy dish served on Shavuot." The Venetians incorporated Muslim flavorings in their spinach dishes(2).
Florence native Catherine de' Medici, who became France's queen in 1533, actually craved spinach to where she ate it every meal! Thus we call spinach dishes "Florentine" (1). "In the seventeenth century, the famous English philosopher John Locke reports having had a spinach and herb soup during his travels in southwestern France"(2).
References:
1. "Spinach History - Origins of Different Types of Spinach." Vegetable Facts. Vegetable Facts. Web. 5 Feb. 2021. http://www.vegetablefacts.net/vegetable-history/spinach-history/.
2. "The Origin and History of Spinach." Food History. History of Science. 27 Sep. 2006. Web. 5 Jan. 2021. https://www.world-foodhistory.com/2006/09/origin-and-history-of-spinach.html.