Allow me to address some of the many flaws in House Targaryen. Even though I will always be a fan of this infamous family, I cannot shake off their flaws. Among those flaws was the fact that they were very careless and irresponsible with their heirlooms compared to other noble houses.
To begin with, the Targaryens lost the Valyrian steel crown of Aegon the Conqueror when Daeron the Young Dragon attempted to conquer Dorne. Since then, Targaryen kings replaced it with inferior crowns that any normal king would wear. Because Valyrian steel is so rare and impossible to make from scratch, that crown was irreplaceable. When House Arryn ruled as Kings of the Vale, they had a collection of crowns they had worn for thousands of years until Visenya Targaryen took them away.
While we are on the subject of Valyrian steel, let’s turn our attention to the two Valyrian steel ancestral swords of House Targaryen: Blackfyre and Dark Sister. Most noble families were super lucky if they even had one Valyrian steel sword, but the Targaryens had TWO!!! Then they squandered both swords at the start and end of the five Blackfyre Rebellions. The noble families who had Valyrian steel swords such as the Starks, Mormonts, and Tarlys took great care of their ancestral blades and had them for five hundred years. With the Targaryen Dynasty, they lost both of their ancestral blades after having them for less than two hundred years.
Thanks to the Mad King’s insanity and tyranny, the Targaryen Dynasty lost the Iron Throne; the seat of absolute power that they held for almost three hundred years. If it wasn’t for the Targaryen family curse of madness and had the sense of giving up their practice of incest, the Targaryens could have ruled Westeros until the end of time.
However, even though the Iron Throne served as a symbol of the Targaryen’s power, the true source of their power came in the form of their greatest weapons: DRAGONS!!! For over a century, the Targaryen Dynasty were able to hold onto their power thanks to their dragons. With the exception of the Dornishmen and the zealots of the Faith Militant, no one was crazy enough to wage war against dragons. Then the Dance of the Dragons came along and the Targaryens lost their dragons along with the long term lynchpin to their hold to the Iron Throne. Instead of being responsible with their dragons, the Targaryens regarded them as weapons and they paid the price for this neglect.
I breaks my heart that the Targaryens did not take better care with all of their heirlooms. They truly had it in them to rule Westeros forever if they had taken the proper steps to prevent their downfall.