Sebald or Sebalt de Weert (May 2, 1567 – May 30 or June 1603) was a Dutch captain and vice-admiral of the Dutch East India Company (known in Dutch as Vereenigde Oost-Indische Compagnie, VOC). He is most widely remembered for accurately plotting the Falkland Islands in 1600.
Sebald de Weert was born in Antwerp, the sixth of 17 children of Johannes (Jan or Hans) Sweerts de Weert (b. 1538) and Clara (Claartje) Wonderer (1541–1595). The family soon (Jan 10, 1569) left Antwerp for Cologne, in Hans' own words to escape the "tyranny and persecution". In 1575/6 the family moved to Amsterdam, between 1579 and 1584 they were back in Antwerp, and by 1586 they lived in Middelburg. Sebald was originally employed as a ship's navigator with the VOC (in Middelburg?), and over the years worked his way up to vice admiral in the Dutch East India Company. He signed his name "Sebalt", but had the official Latinized name "Sebaldus", and has often been referred to in English and French as Sebalde de Weert, and in Spanish and Portuguese as Sebaldo de Weert.
Around 1598, several exploratory expeditions left Rotterdam for eastern discovery traveling in many different routes. On June 27, 1598, a voyage of five ships with 494 men under the command of Jacques Mahu and financed by Pieter van den Hagen and Johan van der Veken, two wealthy Dutch retailers, and equipped by Magelhaanse Compagnie, left Goeree (Holland), bound for the Moluccas, in the Dutch East Indies. They headed Southwest toward the Straits of Magellan in South America, intending to navigate the straits then turn Northwestern toward Asia.
The ships with their (initial) captains were: Hoop (Hope), captained by Jacques Mahu, leader of the expedition; Liefde (Love), captained by Simon de Cordes, second-in-command; Geloof (Believe), captained by Gerrit van Beuningen; Trouwe (Faith), captained by Jurriaan van Boekhout; and finally Blijde Boodschap (Good Tiding or The Gospel), captained by Sebald de Weert. The Blijde Boodschap was better known as Vliegend Hart (Flying heart) prior to this particular voyage. Liefde had been previous known as Erasmus and still had a figurehead of him.