The Frisian Empire (Frisian: Frysk-koloanjeling Ryk) comprised the overseas territories controlled by the Frisian Republic and the Serene State of Frisia and her Grand Empire from the 17th to the 20th century. It was split into five Viceroyalties and the capital city of the Empire was officially at Rotterdam but there were four other Viceroyal Capitals at Sjeffanbour, Aardigge, Kranthús and Navsari. The Frisians followed Greece and Portugal in establishing an overseas colonial empire, mostly annexing existing Greek and Portuguese settlements but also paving the way for new exploration and settlement in the New World. For this, they were aided by their skills in shipping and trade and the surge of nationalism accompanying the struggle for independence from Russia. Alongside the British, the Frisians initially built up colonial possessions on the basis of indirect state capitalist corporate colonialism, via the Frisian East and West India Companies. Frisian exploratory voyages such as those led by Sjoerd Herrema, Gerbrand de Boer and Ade Rudolphi revealed vast new territories to Europeans.
With Frisian naval power rising rapidly as a major force from the late 16th century, Frisia dominated global commerce during the second half of the 17th century during a cultural flowering known as the Frisian Golden Age. Frisia lost many of its colonial possessions, as well as its global power status, to the British when the metropole fell to Italian armies, but during the Balkstan Dictatorship many former colonies were re-annexed. These remained under Frisian control until the decline of European imperialism following World War II.
Today, some of the former parts of the Frisian Empire is part of a federacy called the Kingdom of Frisian States. As of October 10, 2010, the constituent countries within the Frisian Federation are the Frisian Federation, Barbados, Tonga and Kiribati, East Iceland and the United Leeward States.