Let's do some refinement. The Romanov dynasty began with the Tsar Michael Fyodorovich Romanov (1596-1645).

Tsar Mikhail himself chose as his wife (Khlopova, Maria Ivanovna) a girl from the impoverished noble family of the Khlopovs.

This was done bypassing the desire of his mother Tsaritsa Ksenia Ioannovna Romanova. His mother wanted him to marry the Saltykov family of nobles (one of the most influential families in Russia). Actually, in Russia it was considered normal to marry women from relatively modest noble families, the presence or lack of money does not affect your nobility. In addition, the Kings are ordinary people, they also want to find a woman who they like. But nature does not guarantee that in a richer or more influential noble family, there will be beauties. Therefore, it was considered normal if the king chose his wife not only with his head, but also with his heart. Because of this, the history of Russia is similar to the Game of Thrones. Envy existed among the noble families, they did not like that the next Tsar could, at the behest of his heart, choose a girl from an absolutely ordinary noble family, and deprive the authorities of more powerful families. Needless to say, what were the problems because of this? poisoning, killing, etc.

Why did the Russians begin to marry foreign women?

The reason Russian emperors chose foreign princesses as their wives is actually quite prosaic. It was predetermined by the system of transfer of power that developed in the Russian Empire at the turn of the XVII-XVIII centuries.

In 1797, Paul I adopted the Act of Succession. This document was intended to put an end to a series of palace coups that followed the death of Emperor Peter I. (Peter I did not leave an heir)

The Pavlovsky Act introduced “inheritance by law” and the advantage of male descendants, and also forbade emperors unequal and closely related marriages. This point became most effective in 1820, when Emperor Alexander I supplemented the document with the norm according to which children born in an morganatic marriage were deprived of the right to the throne.

Because of this, in order to continue his family and at the same time prepare a full-fledged heir, the sovereign had to look for an equal pair abroad.

Why did brides get out of the small duchies? Well at that time, what we now call Germany was an accumulation of various small duchies. The territory of Germany was a market-brides of noble blood. And actually the Germans were most familiar to the Russians among other foreigners. The first written mention that German merchants were doing business in Russia dates back to the 12th century. In short, the Germans were the largest foreign group from western Europe in Russia. This trend continued until Stalin came to power.

It is logical that the first foreigners whom the Russian Tsars drew attention to were Germans, and peoples related to them (for example, Danes)

Why, for example, are not Spaniards? Well, did you see how the representatives of the Habsburg dynasty looked?

Let me remind you, despite the fact that the Russian Tsars were forced to look for brides abroad, this does not mean that they should have married the freaks that they did not like. The Baltic peoples were also popular, they were also well known to the Russians. You can add here and the Swedes. Russia was also familiar with the Swedes for a long time. Russia fought with Sweden since the 11th century, so the Russians managed to recognize them during this time.

Foreign marriages are rare, but occurred before the Romanov Dynasty. For example, Ivan III the Great, married the daughter (grandmother of Ivan the Terrible) of the last Byzantine emperor from the Paleolog dynasty. After that, Russia began to consider itself the heiress of the Byzantine Empire. The coat of arms that you see today in Russia is actually based on the family coat of arms of the Paleologists dynasty.

What is the outcome? The Russian Tsars tried to marry foreigners who were previously familiar to the Russians, these were mainly the Baltics, and the Germans.

P.S.Regarding the English royal family. I don’t know for what reasons there were no marriages between the British and the Russians, perhaps because England is very far away. But there was an interesting case, the English Queen Victoria and the heir to the Russian throne, Alexander the Second, had a romatic relationship. Such a marriage was completely excluded, she is the Queen of England, he is the future Tsar of Russia.

This is the entry Victoria made in her diary: “At a little after 12 we went into the dining-room for supper; after supper they danced a Mazurka for ½ an hour, I should think nearly; the Grand-Duke asked me to take a turn, which I did […] the Grand-Duke is so very strong, that in running round, you must follow quickly, and after that you are whisked round like in a Valse, which is very pleasant […] I never enjoyed myself more. We were all so merry; I got to bed by a ¼ to 3, but could not sleep till 5.”

Who knows, who knows how it would end under other circumstances.

I hope my English will be readable.