Geekosystem categorized types of swords seen in Hollywood movies into 10 archetypes. Starting the list is the Ancestral Sword:
The ancestral sword is usually a gift (or yours by birthright), something that you take because, well, it's dangerous to go alone. Maybe it's been in your family for generations. Maybe you pried it from the cold, dead hands of your loved one and swore to avenge his death with the very same blade. Whatever floats your boat.
It's very likely that the weapon's significance will be so great that it will be destroyed as part of the 2nd act climax and your eventual replacing of it will be used to symbolize that you have come into your adulthood and stepped out of the shadow of your parent.