I am watching a documentary on the last czar and how his son had hemophilia. I get why he'd do anything to keep his son safe but I don't understand why they need a male heir. By thus point the royal families of Europe were massive so it should be a fairly simple matter to find a male cousin or brother that would keep the family line going. Why did so many people in the courts of Europe obsess about every single monarch having a son?
There's more to be said as this is a massive question, but I discuss why the optics regarding heirs were important for the tsar in this previous answer to Why did Tsar Nicolas the II keep information regarding his sons illness private?