Answer:
The English Channel is the strait that separates England from France, and the British Isles from the European mainland. It is around 560 km long and varies in width from 240 km at its widest to 33.1 km at its narrowest at the Dover Strait, between Dover and Calais.
The English Channel has always functioned as a natural defensive barrier that has prevented Britain from being invaded by various cultures. The Romans and Normans managed to invade Great Britain, but if this channel had not existed, invasions would have been much more common. In fact, the English Channel is one of the main factors why Hitler never invaded the United Kingdom in World War II.
This separation, in addition to functioning as a defense method, has also meant a cultural barrier in antiquity. The fact of being separated from the continent made Britain and Ireland have a much more traditional and distinctive culture than that of their continental European neighbors. Although the exchange was fluid, the distance and the inability to connect quickly and spontaneously generated very different cultural manifestations on these islands compared to those that occurred in Continental Europe. Thus, we find certain unique characteristics in these islands, such as the Scottish and Irish tribal culture, the mythology of dragons and castles in Wales, and in general the language and artistic development, which remained far from the rest of Europe until the development of mercantilism and the beginning of trade exchanges.