Taxation in the Middle Ages: what did the Domesday Book and Magna Carta change?

To levy a tax, you first need to know what to levy it on. Medieval England answered these two problems with two famous documents.

• The Domesday Book (1086). On the orders of King William, who had conquered England, the lands, their owners, the labour force and the livestock of the whole country were recorded. It was, in effect, a huge "register of the tax base".
• Its purpose is debated. The UK National Archives says that the book's most obvious purpose was to help the king make full use of taxes and resources and to record who owned what. Historians also suggest other purposes.
• Magna Carta (1215). An agreement between King John and the barons. Its clause 12 states that the king could not levy "scutage" (a payment in place of military service) or "aid" (an extraordinary levy) without the common counsel of the kingdom.
• Three exceptions. A levy without the counsel was allowed only to ransom the king from captivity, to knight his eldest son and to marry his eldest daughter once.
• The clause did not last long. In 1216 clause 12 was deferred for further discussion, and later versions mention only scutage.
• The main legacy. The idea that "a tax is imposed by agreement, not at the ruler's sole will" became the foundation of the parliamentary and budget system in the following centuries.

Example (prepared by the author, hypothetical). For Odo, a village miller, a Domesday entry might have looked like this: "1 mill, 2 ploughlands, 6 pigs". Looking at this line, the king's scribe assesses how much can be taken from the mill. In today's language, the entry is the tax base and the scribe's assessment is the tax calculation.