It covered an area in the Scheldt and Meuse delta roughly corresponding to the modern Dutch province of Zeeland.

In 1012 Emperor Henry II the Saint enfeoffed the French count Baldwin IV of Flanders with Zeeland after which both counties were ruled in personal union, contested by northern Holland from the beginning.

After the death of Mary of Burgundy in 1482, Zeeland according to the Treaty of Senlis was one of the Seventeen Provinces held by the House of Habsburg, which in 1512 joined the Burgundian Circle.

Both before and after Dutch independence Zeeland shared some institutions with the States of Holland and West Friesland, such as the supreme court, the Supreme Council of Holland, Zeeland and West-Friesland, after the northern provinces had removed themselves from imperial authority and the jurisdiction of the Grand Council of Mechelen.

As a (theoretically) independent (part) state the county Zealand ceased to exist under the Batavian Republic in 1795, when it became a département.