Question: When is the new peer properly addressed by his title after the death of the previous title holder?

The man is the peer immediately,  and servants, solicitors and such might address him by his new title, but it was a matter of courtesy to the widow and any children to wait until after the funeral. It wasn’t a legal matter but more a matter of etiquette. Because it wasn’t a matter of law but of custom, there was a wide variation in observance.

The British nobility in the narrow sense consists of Peers. Members of the peerage carry the titles of duke, marquess, earl, viscount or baron (in Scotland historically lord of parliament). British peers are sometimes referred to generically as lords, although individual dukes are not so styled when addressed or by reference, and those holding some offices are afford the title “Lord” by courtesy.

All modern British peerage dignities are created directly by the Crown and take effect when letters patent are issued, affixed with the Great Seal of the Realm. The Sovereign is considered to be the fount of honour and, as “the fountain and source of all dignities cannot hold a dignity from himself”, [Opinion of the House of Lords in the Buckhurst Peerage Case] cannot hold a British peerage. Peerages inherited by the Crown, for example those held by the Prince of Wales upon the demise of the monarch, merge with it and can be regranted to a new individual.

Membership in the Peerage is strictly personal and for life (life peerages) though often heritable (hereditary peerages) primarily by agnatic primogeniture with some exceptions. All British subjects who are not themselves Peers of the Realm are technically commoners, regardless of ancestry, wealth, or other social factors. This includes Princes of the United Kingdom who have not yet been granted a Peerage. The term “Commoner” does not imply that the person is not noble in the Continental sense, but rather that he is not a Peer and is therefore entitled to be elected to the House of Commons.

Unlike the feudal titles they replaced, peerages are personal title that cannot be transferred, bought, or sold by the title holder. Historically monarchs sold peerage titles under limited circumstances. This was often done to raise funds. For example, in the early Stuart period, King James I sold peerages, adding sixty-two peers to a body that had included just fifty-nine members at the commencement of his reign. Some governments through history also sold peerages to fund government activities, or more controversially, party activities. The selling of peerage grants by a government was made illegal in 1925 with the Honours (Prevention of Abuses) Act 1925. The act was the result of the administration of David Lloyd George selling a high number of controversial peerages. The Blair administration was later accused of trying to skirt this law in 2006 in the so called “Cash-for-Honours scandal”, as was an aide of Prince Charles in the 2021 Cash-for-Favours scandal.

Question: So if the heir had an honorary title of viscount, they might call him to the house under that title?

No. He would only be called to the House of Lords in his father’s barony– if the father had one.

He would be a Viscount socially but a baron in Parliament.

Question: Along the lines of a guardian being assigned for insanity, what about physical incapacity like chronic illness or stroke? Would an earl’s heir have to take over House duties, or would that seat just remain empty?

No one could attend the House of Lords in a peer’s place while he is alive. What could be done, if the peer is an earl or higher, is to call the heir to the House of Lords on an accelerated writ in one of his father’s baronies. Otherwise, the seat remains empty during his lifetime.

That happened when the Earl of Portsmouth was officially declared mentally incompetent.  He was still earl even though he was not sent a writ to attend the House of Parliament.

Question: Does the next in line need to get hold of the title? If the son is crazy or otherwise incapacitated, perhaps the next in line could be made his guardian and manage the affairs of the earldom. In other words, be the earl in all but name.

If a peer is “crazy” a commission is appointed to see to his affairs and a guardian is appointed to care for his person. This would not be the person who could inherit if he died.

However, the heir could be appointed to care for the lands and property under the umbrella of the commission set by the court in Chancery.

Though the peer is unable to attend Parliament or marry, he is still the peer and no one can take his seat or have his privileges until he dies.

Once a person has been accepted as the new peer and has received his writ of summons to the House of Lords, any who wants to unseat him are unlikely. Parliament does not readily, or perhaps, ever, admit to mistakes so if a person is sent a writ of summons, that means the person is a peer.

All questions of legitimacy or who is the heir has to be determined after the death of the current peer and before the reception of a writ by the applicant, whether the next peer is the son or some distant cousin.

Two men claiming as cousins to a recently deceased peer put forth their claims to a peerage. Both presented  boxes of documentation. After much deliberation, one of the men was declared to be the rightful heir and was seated as the peer. The loser came back with a document he said proved that the other man was actually illegitimate. He was told “Too bad. Sorry, but the evidence should have been presented earlier.”  

Take as one example the dispute between Shedden v. Patrick, a lengthy and complex legal dispute concerning a Scottish peerage and questions of legitimacy. 

• Contesting Claims: Two individuals (cousins) vying for a peerage, each presenting extensive documentation to support their claim.
• Illegitimacy as a Key Issue: The central point of contention revolved around the legitimacy of William Shedden’s children, and their right to inherit properties in Scotland.
• Differing Interpretations of Law: The claimants’ arguments were based on contrasting legal interpretations regarding the legitimation of children: Scots law (legitimation upon marriage of parents) versus English common law (children born illegitimate not legitimated by subsequent marriage).
• Late or Undiscovered Evidence: The consequences of late evidence submission in such cases is apparent in this situation. The Shedden v. Patrick litigation dragged on for decades, highlighting the difficulty of altering established legal decisions based on new information. 

This case exemplifies the intricate legal and societal considerations surrounding peerage succession, particularly when questions of legitimacy and differing legal systems were involved. 

For another example, look at the Sussex Peerage Case of 1844. In a claim of Peerage, where the question was whether the deceased Peer, the father of the claimant, had been married or not, a Prayer-book, found after the death of the claimant’s mother among her papers, was received, and an entry made in her handwriting, declaring the tact of the marriage, read from it, not as conclusively proving that fact, but as a declaration of it made by one of the parties at the time.