Urisland / Ounceland

Land assessed to render one ounce of silver in tax to the Norse crown.

The urisland measures tax rather than ground. It is the extent of land that rendered one ounce of silver to the Norse crown, so a fertile holding and a poor one of the same assessment could differ enormously in acreage.

It is also called the ounceland, and in Gaelic the tirunga — tir-unga, the land of an ounce, a direct translation. It appears across the whole zone of Norse settlement: the Hebrides, Orkney, Shetland, Caithness, and the Isle of Man, where the same system produced the treen and the quarterland.

It divides into pennylands, twenty to the ounceland by the usual reckoning, though some districts divided into eighteen instead. Whether those variations reflect different original systems or later subdivision is unresolved.

It has no conversion to acres, and attempts to supply one are misleading. A unit defined by what land yields cannot be restated as a quantity of land.