法蘭克福的歷史可以上溯到公元元年前后，那時萊茵河和多瑙河是羅馬帝國的北方邊界，但兩河并不相連，其間無險可守，因此羅馬人修筑了連接兩河的長城。這座長城固然不能與中國的長城同日而語，但也連綿數(shù)百里，從法蘭克福附近經(jīng)過。于是人們在這里設(shè)置了駐軍營地，這一帶成為邊境要塞。隨著羅馬帝國的崩潰，這時軍營圯毀，日漸荒蕪，幾乎被人遺忘，直到8世紀(jì)才再度興起。傳說，一天拂曉，漫天大霧，查理大帝打了敗仗，逃到美茵河邊，找不到向?qū)?，無法渡河。危急之中看見一只母鹿，朝水邊走來，他注意看那鹿，果然，這只鹿涉水過河了，大軍也隨之過河，轉(zhuǎn)危為安。為了紀(jì)念這件事，查理大帝下令在當(dāng)?shù)亟ㄖ蛔鞘?，取名法蘭克福，意思是法蘭克人（日耳曼民族中的一支）的渡口。公元794年法蘭克福作為查理大帝的行都首次載入史冊。

The history of Frankfurt can be traced to before and after AD year one. Back then， Rhine and Danube were the northern border of the Empire of Rome， but the two were not connected， therefore the Romans built Great Wall connecting rivers. The Great Wall stretched for hundreds of miles， passing near Frankfurt. So people set up a garrison camp here， a frontier fortress. With the collapse of the Empire of Rome， this camp was destroyed and increasingly barren， almost forgotten. Until eighth Century it rose again. Legend has it， one foggy day at dawn， Charlie the great was defeated， fled to the Main river， but he can not find the guide to cross the river. Then he saw a deer walked toward the water and waded across the river. So the army followed. To commemorate the event， Emperor Charlie ordered to build a city named Frankfurt， meaning the port of the Franks （a Germanic ethnic group）. In AD 794， Frankfurt is recorded first time in the history in Emperor Charlie's territory.