Of all such personal devices, seals have had the most universal and continuous application. In classical times they were used to authenticate documents, and the Frankish kings preserved their use throughout the dark ages. These seals were normally impressed upon wax on the document itself, but Edward the Confessor in the eleventh century originated the custom, still employed by some today, of impressing his Great Seal upon wax and affixing the wax impression by cord to the document, thus allowing the seal to become two-sided.
The seal was personal to the owner, but as the years went by it gradually acquired a hereditary significance, and the device on the seal was passed from father to son.
The Governor of the Crown Colony of Hong Kong has possessed and used a public seal since 1843. The authority for this seal resides in Article IV of the "Letters Patent passed under the Great Seal of the United Kingdom, constituting the Office of Governor and Commander-in-Chief of the Colony of Hong Kong and its Dependencies". This Article states quite simply:
"The Governor shall keep and use the Public Seal of the Colony for sealing all things whatsoever that shall pass the said Public Seal."
This offers little guidance on what things "shall pass the said Public Seal", and its use is in fact determined by custom and by reference to the use of the Great Seal of the United Kingdom. The Great Seal is employed by Her Majesty the Queen for the issue of writs for parliamentary elections and to summon peers to sit in Parliament, for treaties, for Letters Patent constituting the office of Governor of a Colony and making provision for the Government thereof, and for authenticating all public instruments and orders of State which relate to the whole Kingdom. (Wade & Phillips' Constitutional Law, p. 500).
In Hong Kong, the public seal is used principally for sealing all Ordinances made by the Governor "by and with the advice and consent of the Legislative Council", and for sealing Proclamations and other important documents bearing the Governor's signature.
A seal is a personal device, and the Public Seal of the Colony bears the name of the reigning Sovereign and denotes her Majesty's authority exercised through the Governor as the Queen's representative. The old seal must therefore be defaced and a fresh seal obtained on the accession of a new Sovereign; but it need not be changed upon the appointment of a new Governor.