The Heirloom Seal of the Realm was a political philosophy. It represented a legitimising device for every emperor's right to rule. Heaven—which embodies the natural order and will of the universe—bestowed the mandate on a just ruler, the Son of Heaven.
The one which possessed the seal could declare himself the legitimate heir—even if not from the royal blood lineage.
The jade seal symbolised prosperity, heavenly wisdom, power and immortality. The loss of the Heirloom Seal of the Realm, this was interpreted by superstitious beliefs as an indication that the ruler was unworthy and had lost the Mandate of Heaven. It signalled Heaven's displeasure with the emperor, and thus could become the object of armed conflict and valid grounds to overthrow the current ruler. A right for a new regime to uprise.