Dutch treat. Beat the Dutch. In Dutch. Going Dutch. Double Dutch.
What is with all the Dutch? A long time ago, the Dutch were a major naval and trading power across the North Sea, where Britain resides. Naturally, Britain and Holland were nautical enemies. While the two were in-between battles, Britain would come up with rude sayings to offend the Dutch with.
Dutch courage is courage found at the bottom of a bottle, and a Dutch comfort is no comfort at all. A Dutch wife is a large pillow based on the presumption Dutch women were poor bed companions. Dutch treat is no treat at all; everyone pays for themselves. Going Dutch are for tight-fisted diners, and a Dutch widow is a prostitute. A Dutch bargain is no bargain at all, and a Dutch auction is an auction that opens with a high bid and works downward.
In 1934, the Dutch government finally caught wind of the sayings and decided it was too late in the game to change the English language. Their response: make it a rule that their ambassadors in English-speaking countries use the term The Netherlands.
The Dutch most likely had sayings in their language about the English, but nobody knows what they are since the language is double Dutch to us. Once Dutch was used up, the English went on to Welsh: Welsh carpet is a pattern painted or stained on a brick floor; a Welsh diamond is a rock crystal; and a Welsh comb is your fingers.
When the English were done with the Dutch and Welsh altogether, they moved on to the Irish where we have Irish stew (stew from leftovers), and nonsense itself is referred as Irish.
Although, the real question lies: has anyone beaten the Dutch?*
*A person who told a completely incredible story.