Eberhard III, Duke of Württemberg

Eberhard III (16 December 1614, Stuttgart – 2 July 1674, Stuttgart) ruled as Duke of Württemberg from 1628 until his death in 1674.

Eberhard III became the heir under guardianship in 1628 during the Thirty Years' War at the age of 14 after the death of his father, Johann Frederick, 7th Duke of Württemberg. His guardian at first was his father's brother Louis Frederick, Duke of Württemberg-Montbéliard and after his death in 1631 Julius Frederick, Duke of Württemberg-Weiltingen.

Württemberg lost around one third of its territory in 1629. Julius Frederick was removed as guardian in 1633 when Eberhard was declared of full age at which point he assumed full rule of the Duchy. Following a major defeat of Württemberg troops in the battle of Nördlingen on 6 September 1634, Württemberg was severely looted and plundered.

Eberhard fled to Strasbourg, where he married in 1637, returning to Württemberg in 1638 after long negotiations with Ferdinand III of the Holy Roman Empire. By this time many territories had already been passed on by the Emperor to other parties to push forward Catholicism in the region.

The Duchy of Württemberg was reinstated after long negotiations resulting in the Peace of Westphalia of 1648, despite or maybe because of the effects of war, poverty, hunger and the Bubonic plague all of which reduced the population from 350,000 in 1618 to 120,000 in 1648.

Eberhard III entered into an inheritance agreement with his younger brother Frederick thereby handing over ownership of the Duchy of Württemberg-Neuenstadt and thus establishing a new branch line of the duchy. In 1651, Eberhard came to a similar agreement with another brother, Ulrich affecting the Castle of Neuenbürg.