What is the meaning of dynastic diplomacy in Europe in 17-19 cc?

Diplomacy among the "Ruling Royalties" in this period time can be called dynastic diplomacy. From the 18th to the early part of the 20th centuries, European monarchs still ruled their nations and their empires. The power of the ruling monarch began to diminish after the first world war, however, before that the monarchs of such nations as Britain, France, Spain, and Russia to give some examples, had a strong sense of dealing with their fellow monarchs in Europe.