Frankonovurd (in old high German) or Vadum Francorum (in Latin) were the first names mentioned in written records from 794. It transformed to Frankenfort during the Middle Ages and then to Franckfort and Franckfurth in the modern era. According to Czech historian Dovid Solomon Ganz, the city was named by its builder in circa 146 CE, one of the kings of the Franks whose name was Zuna and who ruled over the province then known as Sicambri. He hoped, thereby, to perpetuate the name of his ancestors, the Franks.
By the 19th century, the name Frankfurt had already been established as the official spelling. The older English spelling of Frankfort is now rarely seen in reference to Frankfurt am Main, although more than a dozen other towns and cities, mainly in the United States, use this spelling (e.g., Frankfort, Kentucky; Frankfort, New York; Frankfort, Illinois).
Year 1899. City of Frankfurt am Main.
The affix "am Main" has been used regularly since the 14th century. In English, the city's full name of Frankfurt am Main translates to "Frankfurt on the Main" (pronounced like English mine or German mein). Frankfurt is located on an ancient ford (German: Furt) on the Main River. As a part of early Franconia, the inhabitants were the early Franks, thus the city's name reveals its legacy as being "the ford of the Franks on the Main".
Among English speakers, the city is commonly known simply as Frankfurt, but Germans occasionally call it by its full name when it is necessary to distinguish it from the other (significantly smaller) German city called Frankfurt in the federated state of Brandenburg, Frankfurt (Oder), on the Polish border.
Frankfurt lost its independence after the Austro-Prussian War in 1866 when Prussia annexed several smaller states, among them the Free City of Frankfurt. Frankfurt had stayed neutral in the war, but its free press was a thorn in the eye of the Prussians and they simply used the opportunity to occupy the city by force: Bismarck had been an ambassador to the German Confederation there and constantly quarrelled with the local press.
The Prussian administration incorporated Frankfurt into its province of Hesse-Nassau. The formerly independent towns of Bornheim and Bockenheim were incorporated in 1890.