Autonins Heinsius, grand pensionary of Holland, born in 1641, died at the Hague, Aug. 13, 1720. He was an intimate friend and confidential agent of Prince William III. of Orange, and during 40 years was the moving spirit of Dutch politics. After William became king of England (1680), Heinsius managed for him, greatly to his satisfaction, the affairs of Holland, and was instrumental in rendering the states general favorable to friendly action with England. The grand alliance on the subject of the Spanish succession, between the emperor, the kings of England, Prussia, and Denmark, Holland, the duke of Savoy, and the elector of Hanover, against Louis XIV. and Philip V., was in great measure due to the exertions of the grand pensionary. The defeats of Blenheim (1704), Ramillies (1706), and Turin (1706), with their results, compelled Louis XIV. to open negotiations. He made overtures to Holland; but Heinsius answered that the Hollanders were inseparably bound to their allies, and exacted as a preliminary condition the recognition of the right of the house of Austria to the Spanish succession. To this France refused to accede; the war was continued disastrously for her, and in 1709 her renewed application met with the same response.

Louis XIV. now consented to treat on this basis, and negotiations were commenced; but the allies demanding still greater sacrifices, he renewed the war, and after the defeat of Malplaquet (1709) conferences were again opened at the castle of Gertruidenberg and continued unsuccessfully for four months, Heinsius obstinately adhering to his terms. France, everywhere beaten, was in great danger when, in 1711, Queen Anne of England secretly offered peace to Louis XIV. The congress of Utrecht, opened in January, 1712, resulted in England's ceasing hostilities; but Prince Eugene, the Hanoverians, and the Dutch persevered in the war, and took Le Quesnoy, July 4. The defeat of the allies at Denain (July 24) changed the whole state of the war. In a few days several important places were recaptured by the French, and armistices were separately concluded with England and Portugal. Notwithstanding these reverses, Heinsius did all in his power to prevent a general peace. In spite of his efforts, one was agreed upon and signed at Utrecht, April 11, 1713, but the signature of Heinsius was the last affixed.

He died seven years later, while vigorous in mind and body.