1. Sometimes, they do merge their names; for example, Tan-ganyika + Zan-zibar $\rightarrow$ [Tanzania](https://en.wikipedia.org/wiki/Tanzania). 2. Italy [was a *place*](https://en.wikipedia.org/wiki/Italian_Peninsula) before it was a country. It is pretty natural for a country which occupies the Italian Peninsula to call itself Italy. Two and a half millennia ago, it was the name of a small region at the southern end of the peninsula. The Greek colonists asked the locals what was the name of the country, and the locals answered *Witeliu*, Land of Young Bulls, which the Greek wrote *Ouitalia*, which later became simplified to *Italia*. In time, the name was extended to include the entire peninsula; already in the 1st century BCE Strabo uses the name to refer to the entire country south of the Alps. 3. Greece was a place and Greek was a language loooong before the Hellenic Kingdom was a thing; like two and a half millennia before. Ruling over Greece-the-place and Greeks-the-people was the entire purpose of the Hellenic Kingdom; this is why it was named the Hellenic Kingdom. Note that in their own language the Greeks call themselves Hellenes, and their country Hellas. The name Hellas was used for the entire area inhabited by Greek speaking people since a very long time ago, at least since the 5th century BCE. We call them Greeks in English because the Romans called them Greeks; the Romans called all the Greeks, Greeks, because the first Greeks they met were from north-western Greece, and did call themselves Graikoi, which was naturally Latinized as Graeci. 4. German was a language, and Germans were a people long before His Majesty [William I](https://en.wikipedia.org/wiki/William_I,_German_Emperor) was proclaimed emperor of the new German Empire. It was called the German Empire because its people were Germans, and it was the successor state of the North German Confederation. The North German Confederation was called the North German Confederation because it contained the states in the northern part of the area where the German language was spoken. Before the North German Confederation there was the Holy Roman Empire of the German Nation, established a thousand years ago. Note that in their own language the Germans call themselves Deutsche, and their country Deutschland. We call them Germans in English because the Romans call them Germans. Why the Romans called them Germans we have no clue. 5. I have no idea what you mean by giving the example of China. China is not called China in Chinese; *we* call it China. In Chinese it is called Zhōnghuá, "Central Essence" (or Central Nobility, or Central Eminence, etc., the second component of the compound name being quite polysemantic). Before the current People's Republic and the very much reduced Republic of China, there was the Chinese Empire, which called itself Zhōngguó, "Central Kingdom". Pretty neutral names, which don't give any preference to any of the components, which were anyway united a very long time ago. We call China, China, from the name of the [Qin Empire](https://en.wikipedia.org/wiki/Qin_(state)), which occupied the western half of what is now China when the ancient Greeks got to learn about it. (Qin is pronounced not very different from the English word *chin* in Modern Standard Mandarin, and was pronounced, probably, *dzin* two thousand years ago.) 6. To add to the list of examples, my own country is called Romania because most of the inhabitants speak Romanian. The name of the language was always Romanian, as far as we can tell. When Wallachia (which we did not call Wallachia in our own language) and Moldavia [united in 1859](https://en.wikipedia.org/wiki/United_Principalities_of_Moldavia_and_Wallachia) there became apparent a need for a name for the new united country; what was more natural than to name the country after the language of its people? 7. Another example is [Yugoslavia](https://en.wikipedia.org/wiki/Yugoslavia), Land of Southern Slavs. All¹ the nationalities, Serbs, Croats, Montenegrins, Slovenes, Macedonians, were indeed Slavic, and they spoken Southern Slavic languages; so, it was indeed a country of Southern Slavic peoples. <sup>¹) All the nationalities except the Albanians, of course. But nobody cared about the Albanians until they absolutely had to care about the Albanians.</sup> 8. The final example is the Netherlands, literally the Low Countries. They are indeed very low, with one quarter of the territory below sea level and the tallest hill barely above 300 meters high. The name Netherlands for the region became current some five hundred years ago. Note that originally the name Netherlands, or the Low Countries, included what is today Belgium. Belgium was [created² by the Great Powers in 1830](https://en.wikipedia.org/wiki/London_Conference_of_1830); the new kingdom needed a name, and, since all the diplomats of that era had a thorough classical education, it was named after the [Belgae](https://en.wikipedia.org/wiki/Belgae), who inhabited sort-of that area in the 1st century BCE, as Caesar informs us. <sup>²) The people of the southern half of the United Kingdom of the Netherlands started a little revolution. The king deployed a ridiculously small number of troops to quell the uprising; they utterly failed to do so, and the attempt inflamed the people, who elected a provisional government and declared independence. At the London Conference, France took a decisive stand in favor of making the Netherlands smaller, and the other Great Powers did not feel inclined to go to war over the matter.</sup>