- The Great Seal: This was the first of the seals to be developed. Under the Norman kings it expressed the personal wishes of the king and authenticated all acts by the king or his government. This remained the case throughout the whole of the Middle Ages but by the thirteenth century the Chancellor, who held the seal, had a large department under him and the seal no longer regularly travelled with the king.
- The Privy Seal: This was originally developed, probably in the early thirteenth century to act as the private seal of the king once the Great Seal was no longer under his immediate control. It was sometimes used as an instrument of government in its own right or to authenticate a message to the Chancellor, from him to issue a document under the Great Seal. The Keeper of the Privy Seal gradually became an important officer of state and was housed away from the court. Thus in turn the Privy Seal was not under the direct control of the king.
- The Signet: The king always needed a seal under his own control, to authenticate private corresondence and to enable him to exercise his authority directly. The Privy Seal no longer meeting this need, various secret seals came into being, of which the most permanent became the Signet, under the control of the King’s Secretary. Sometimes (perhaps always) the king also had a secret seal which was not in the keeping of the Secretary. Edward IV certainly had one. This seal was used as a warrant for the acts of the king and for the issue of instruments under the Great Seal.
A discussion of the Signet in our period can be found in The King’s Secretary & the Signet Office in the Fifteenth Century, by J. Otway-Ruthven, which is in the Society’s Library