Statute of Frauds 1677
The Statute of Frauds is, get this, current English law. It was enacted to meet the danger that certain types of contract (those relating to wills, sureties (guarantees), marriages and land transfers) must be in writing and signed, to avoid fraud on the court by perjury and subornation — or convenient evidence of "loose talk, when it never was really meant to make such a contract" — Steele v M’Kinlay.
It also required that court documents be signed and dated.
While much if it has been replaced in the three and a half centuries since its enactment — Sections 1-3 by the Law of Property Act 1925, and everything from Section 5 by various other miscellaneous bits of 20th Century do-goodery — Section 4 remains on the statute books, as originally spelled at the time of the Glorious Revolution:
Noe Action shall be brought whereby to charge the Defendant upon any speciall promise to answere for the debt default or miscarriages of another person unlesse the Agreement upon which such Action shall be brought or some Memorandum or Note thereof shall be in Writeing and signed by the partie to be charged therewith or some other person thereunto by him lawfully authorized.[1]
It’s of some relevance when you are considering a guarantee and has something to with why you see indemnities tacked onto guarantees: the Statute of Frauds applies to guarantees but not to ordinary contracts.