Nicholas II of Russia
On 1 March 1881, following the assassination of his grandfather, Tsar Alexander II, Nicholas became heir apparent upon his father's ascension as Alexander III. Nicholas and his other family members bore witness to Alexander II's death, having been present at the Winter Palace in Saint Petersburg, where he was brought after the attack. For security reasons, the new tsar and his family relocated their primary residence to the Gatchina Palace outside the city, only entering the capital for various ceremonial functions. On such occasions, Alexander III and his family occupied the nearby Anichkov Palace.
Macedonia (ancient kingdom)
When Philip II married Cleopatra Eurydice, niece of general Attalus, talk of providing new potential heirs at the wedding feast infuriated PhilipII's son Alexander, a veteran of the Battle of Chaeronea, and his mother Olympias. They fled together to Epirus before Alexander was recalled to Pella by PhilipII. When PhilipII arranged a marriage between his son Arrhidaeus and Ada of Caria, daughter of Pixodarus, the Persian satrap of Caria, Alexander intervened and proposed to marry Ada instead. PhilipII then cancelled the wedding altogether and exiled Alexander's advisors Ptolemy, Nearchus, and Harpalus. To reconcile with Olympias, PhilipII had their daughter Cleopatra marry Olympias' brother (and Cleopatra's uncle) AlexanderI of Epirus, but PhilipII was assassinated by his bodyguard, Pausanias of Orestis, during their wedding feast and succeeded by Alexander in 336BC.