Trinoda necessitas is a Latin

Latin

Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...

 term used to refer to a "threefold tax" in Anglo-Saxon times. Subjects of an Anglo-Saxon king were required to yield three services: bridge-bote (repairing bridge

Bridge

A bridge is a structure built to span physical obstacles such as a body of water, valley, or road, for the purpose of providing passage over the obstacle...

s and roads), burgh-bote (building and maintaining fortification

Fortification

Fortifications are military constructions and buildings designed for defence in warfare and military bases. Humans have constructed defensive works for many thousands of years, in a variety of increasingly complex designs...

s), and fyrd-bote (serving in the militia

Militia

The term militia is commonly used today to refer to a military force composed of ordinary citizens to provide defense, emergency law enforcement, or paramilitary service, in times of emergency without being paid a regular salary or committed to a fixed term of service. It is a polyseme with...

, known as the fyrd). Rulers very rarely exempted subjects from the trinoda necessitas, because these services were the lifeblood of an Anglo-Saxon kingdom.

The term "trinoda necessitas" was rarely used in Anglo-Saxon times: its only known use is in a grant of land near Pagham

Pagham

Pagham is a coastal village and civil parish in the Arun district of West Sussex, England, with a population of around 5,500.-Geography:The village comprises three main areas:*Pagham Beach, coastal area, developed in the early 20th Century,...

, Sussex

Sussex

Sussex , from the Old English Sūþsēaxe , is an historic county in South East England corresponding roughly in area to the ancient Kingdom of Sussex. It is bounded on the north by Surrey, east by Kent, south by the English Channel, and west by Hampshire, and is divided for local government into West...

 from King Cædwalla of Wessex to Saint Wilfred. Instead, grants typically described the services individually. In fact, the original grant used the term trimoda (Latin for "triple"); trinoda (Latin for "triple-knotted") was an error introduced by John Selden

John Selden

John Selden was an English jurist and a scholar of England's ancient laws and constitution and scholar of Jewish law...

in 1610.