✔ 最佳答案
All the previous answers are somehow opaque. The real reason is simple: The geographical area of what is Germany now used to be inhabitated by various tribes, such as the Allemannen, the Saxons, the Germanic tribes in general and so on. Now their neighbouring countries chose the most adjacent tribe's name for the entire nation. "Deutsch" originally didn't mean much more than fellow countrymen, applied to all those who lived east of the river Rhine. Hence the Italians have got it all muddled up by calling the country Germania and the people tedeschi, which is a cognate of 'deutsch'. 'Dutch' is quite close too, but has come to mean someone from the Netherlands.