Saxon genitive refers to the formation of a possessive by suffixing an apostrophe (’) and letter s, or in some cases simply an apostrophe, to a noun or noun phrase.
The term is used to contrast such possessives with genitive constructions involving prepositions, typically of. Modern English does not have a true genitive case; the term is a holdover, and references the formation of genitives in Old English ("Anglo-Saxon").
For example, the children’s toys refers to the toys of the children; that helicopters’s tail refers to the tail of that helicopter. But the construction can also be used with more abstract concepts:
Since 1920 both parks have been managed by a private foundation, but the parks’ origins date back to a 1785 decree.
The invaders torched the palace, and the burning’s legacy influences even modern politics.
Questions with this tag may ask about the general usage of the Saxon genitive. For questions about usage compared with the of-genitive, see possessive-s-vs-of. See double-genitive for questions about multiple genitives in a single construction (e.g. friend of Rachel’s).