In 1914, many countries in Europe were ruled by monarchs, and the monarchs of these countries were German and many members of the royal family. Why are so many of them German, considering that some rulers' families date back a thousand years and some only a few decades? This can be explained by one thing, the late unification of Germany.
in the early 18th century. German people are not as unified in Europe as the French, British or Spanish . They were divided into many groups and existed in the form of small kingdoms, many of which had their own monarchs who would marry their children to anyone who had children.
For example, a Prussian princess married the Prince of Orange, a Duchess of Brunswick married the King of Denmark , a Duchess married the King of Sweden , and one from Meck Limbaugh, married to the King of England. Considering these are small countries, marrying them is less risky, whereas marrying a member of the French royal family might raise inheritance issues and French pressure.
The same goes for Norway , although Norway chose a Danish prince for their throne when they split from Sweden in 1905. The royal families of Germany and Austria all originated from the Holy Roman Empire . Over the centuries, they all slowly added to their holdings and titles, from earl to duke to grand duke and king. Before there was an emperor, the Holy Roman Empire didn't have many opportunities for families outside of the royal family to develop, so these families remained German.
Russia also had German royal family . Peter the Great was a member of the Romanov family. His daughter Elizabeth I also died childless, and the throne was passed to his nephew Peter III. Peter's father was the Duke of Holstein, so he was part of the family. Now, Peter and his wife Catherine, keeping the name, associated themselves with their empire and remained in power as long as they did.
Belgium , as a buffer state between Prussia and France, it cannot form an alliance with any country. Therefore, the British kept the men of Sackburg close to Gothard, the husband of the king's niece, to ensure Belgium's independence.
Romania also had a German monarch. When its first ruler, a native Romanian, became authoritarian, he was overthrown in a coup. Since the new country had just broken away from the Ottoman Empire, in order to maintain its independence, the nobles selected a prince from the royal family of Zoran in Prussia. This essentially guaranteed their independence from neighboring Russia, Ottoman, and Austria.
Bulgaria also had royal families from other countries, for similar reasons. Initially, it was ruled by the nephew of the Russian Emperor, but he was overthrown. After a poor performance, he was replaced by an Austrian-backed candidate. The reason why Romania does not choose a German is because Austria and Hungary are not on their borders. After this, these royal families still existed in Bulgaria.