The carucate or ploughland was a unit of assessment for tax used in most Danelaw

Danelaw

The Danelaw, as recorded in the Anglo-Saxon Chronicle , is a historical name given to the part of England in which the laws of the "Danes" held sway and dominated those of the Anglo-Saxons. It is contrasted with "West Saxon law" and "Mercian law". The term has been extended by modern historians to...

 counties of England

England

England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

, and is found for example in Domesday Book

Domesday Book

Domesday Book , now held at The National Archives, Kew, Richmond upon Thames in South West London, is the record of the great survey of much of England and parts of Wales completed in 1086...

. The carucate was based on the area a plough team of eight oxen

Ox

An ox , also known as a bullock in Australia, New Zealand and India, is a bovine trained as a draft animal. Oxen are commonly castrated adult male cattle; castration makes the animals more tractable...

 could till

Tillage

Tillage is the agricultural preparation of the soil by mechanical agitation of various types, such as digging, stirring, and overturning. Examples of human-powered tilling methods using hand tools include shovelling, picking, mattock work, hoeing, and raking...

 in a single annual season. It was sub-divided into oxgangs

Oxgang

An oxgang or bovate is an old land measurement formerly used in Scotland and England. It averaged around 20 English acres, but was based on land fertility and cultivation, and so could be as low as 15.Skene in Celtic Scotland says:...

, or "bovates", based on the area a single ox might till in the same period, which thus represented one eighth of a carucate; and it was analogous to the hide

Hide (unit)

The hide was originally an amount of land sufficient to support a household, but later in Anglo-Saxon England became a unit used in assessing land for liability to "geld", or land tax. The geld would be collected at a stated rate per hide...

, a unit of tax assessment used outside the Danelaw counties.

The tax levied on each carucate came to be known as "carucage

Carucage

Carucage was a medieval English land tax introduced by King Richard I in 1194, based on the size—variously calculated—of the estate owned by the taxpayer. It was a replacement for the danegeld, last imposed in 1162, which had become difficult to collect because of an increasing number of exemptions...

".