Ruriks and Romanovs and possibly Bulgakovs
For centuries, the dynasty that ruled Russia was Rurik (since 862). The founder of the Romanovs, as far as I can tell, was - Andrei Kobyla. who was in the service of a Ruric Grand Prince, Simeon Ivanovich (reigned 1340-1353) and elevated by Simeon to boyar. Many invented genealogies exist for Andrei Kobyla, but it seems clear he was a commoner made a boyar in the 14th century. His family history indicates that they were equerries at that time and for some time afterwards.
One of Kobyla (means "mare") changed his name to Koshkin (apparently a cat lover) and another descendant took up the name Zakharin. Then the family changed its name to Yakovlev while Ivan the Terrible/ Grozny/ Thunderlike reigned, (and Ivan is a Rurik).
The grandchildren of the Zakharin-Yakovlev branch had changed their name to Romanov. Throughout this time, they seem to have been in the service of the Rurik Grand Princes/Tsars. I can't find other examples of boyars changing their names so frequently, that seems unusual.
Then, everything changed when one of their daughters, Anastasia, married Ivan IV (aka the Terrible/ Thunderlike/ Awe-Inspiring; reigned 1533-1584). While it is often said that Ivan killed his only heir, that doesn't seem to be true - the Romanov woman was the mother of the next Tsar, Feodor (still a Rurik). But now, he had Romanov cousins, who were very much interested in taking over.
In the style of Il Moro, Feodor's brother-in-law, Boris Godunov, who was also a boyar and of Tartar origin (partly), began to usurp power after being appointed one of three men to act as counsel/regent to Feodor (one of the other members of that counsel was a Romanov).
Feodor is often called mentally defective, etc., and Boris Godunov is of course famous for grabbing power.
Ivan IV had another son, Dmitri who was also in the official line of succession. It seems likely that Dmitri was murdered by Godunov's operatives. Had he survived, after the death of the childless Feodor I, Dmitri would have been Tsar.
The weakling Tsar, Feodor, still had a Romanov uncle (his mother's brother), to be dealt with by the new Tsar Godunov. When Nikita Romanov died two years after Feodor's coronation, there was nothing to stand in Godunov's way. Godunov had arranged a marriage between Feodor and his own sister, but it remained unproductive of an heir. But, Godunov still had the role of Tsar's father-in-law. Godunov was apparently instrumental in banishing as many Romanovs as possible from Moscow and environs, mostly to the north, where many languished, others waited to come back into royal service.
At any rate, after Feodor's death (still childless), Godunov of course seized the throne. But, given the vast size of the Rurik dynasty, clearly a Rurik heir could have been found, had the effort been made (not that anyone in power wanted to; Godunov was by then known as an able military decision-maker and defender of Russia/Moscow).
Naturally, having taken the title of Tsar, Boris left the crown to his own son, also named Feodor (Feodor II). But both Feodor II and his mother were murdered. After that, a person claiming to be a Rurik (the youngest son of Ivan IV) appeared and falsely took the throne.
The point is: amidst all this chaos, the Romanovs did rise to power, but how can they claim that they did so under monarchic principles?
The Rurik pretender False Dmitry resurrected the Romanov's power (after they had been dispersed by Godunov who justly feared their influence), and Filaret Romanov was made Metropolitan (of Moscow I believe) and eventually a Patriarch of the Church (by the pretender). In some ways, it looks like False Dmitry may have been a Romanov invention or plant.
Eventually Filaret's young son, Mikhail, was offered the crown. These are the Times of Troubles in Russia - no one wanted the throne, apparently people were grateful to Mikhail for taking it, he sought the advice of Ruriks, but the Ruriks essentially wished to be demoted to a position less than Tsar of All Russia (which was a relatively new position, after all). It's also unclear as to whether the offers made to legitimate Ruriks were done in a spirit of optimism, or whether the Romanovs had already decided to take the throne, and merely made gestures of finding legitimate heirs. What amazes me is that Russia thought at the time that a true son of Ivan IV was on the throne (False Dmitry), naturally, it was mostly citizens of Moscow or other large cities that would have heard the whole story.
Whether or not False Dmitry was truly supported by Romanovs, he certainly was supported by Poles. After his marriage to a non-Orthodox (Catholic) woman, the Kremlin was stormed and he was killed. Vasili IV (a Rurik) did take the throne, briefly, until 1612. Two more Dmitri imposters did or tried to as well. Vasili IV had not opposed Tsar Boris, instead, Boris relied upon him and his family to try and ensure that Boris stayed on the throne. When Vasili IV was abandoned by his supporters, a Polish-Swedish Prince was elected by a council of 7 boyars, while other boyars supported the attempt to find another Rurik to rule.
So, by the mid-17th century, the Romanovs were on the throne, but Ruriks still existed (and still do exist). It's obvious that some of Russia's most glorious monarchs were Romanovs and they did a great job of ruling Russia (Peter the Great is one of my favorite rulers), but in terms of questions about monarchic succession, it doesn't seem that only Romanovs should be included in the question.
Shouldn't the Ruriks be taken into consideration? It is quite natural that these houses (of which there are several), should have kept a very low profile in the 20th century, for obvious reasons. I'm just curious, now that Russia is becoming so thoroughly Orthodox again, if the few monarchists in Russia ever consider the Ruriks as possible alternatives to the Romanovs?
Does precedence go to the Romanovs because they accepted the crown and kept it until the lineal heirs were all murdered?
Anyway, I realize that the idea of a monarchy in Russia is incredibly far-fetched. Russia is interesting in the small number of dynasties that have ruled such a large nation, the Ruriks (for 800 years) and the Romanovs (250 years) are practically the only ones (the Godunov branch would be the third - for two generations).
One prominent Rurik family are the Bulgakovs, who do not use their titles at present (and I do not know if the beloved Mikhail Bulgakov is related, but I believe he is).
Does anyone know more about the Rurik-Bulgakovs? I believe that one of them was a Metropolitan of Moscow within the last 150 years or so. The Gediminids of Lithuania are another branch, and I wonder what happened to them after the Soviet revolution.
The Ruriks, btw, are ancestral to Edward III of England (according to wikipedia and an Australian genealogical site), but I can't figure out how. Back in the early days of Rurik rule, they intermarried successfully and frequently with crowned heads of other lands, which is amazing, considering the distances and the difficulties of messaging and traveling.
In Tolstoi's time, Ruriks were still boyars and active in the military (like Denisov), but perhaps they had forgotten their claims to the throne?
Anyway, Ruriks are definitely "non-reigning royals"! I'd be happy to hear more about what became of their various branches, they are spread everywhere (and I suppose that's how some authors have claimed that monarchs of Britain - through Euphrosyne of Kiev - are claimants to a throne in Russia, although I imagine there are several other connections as well).
I sure wish we could have DNA analysis on all those false Dmitris (at the time, it was quite confusing, and Boris Godunov clearly was surprised to find claims that Dmitri was not dead - he sent a Romanov to investigate the circumstance, and that person decided Dmitri had truly died, although the death remained suspicious).
If there are other threads on this topic, please direct me (I'm a bit exhausted looking through the site, which is still very new to me).