This painting is believed to be a portrait of Louis II de Bourbon, Prince de Condé (1621-1686), also known as Le Grand Condé. The Great Condé was an important military commander and a favorite of Louis XIV.
The Prince de Condé was heavily involved in the Thirty Years War (1618-1648). Dynastic territorial ambitions, religious tensions between Protestants and Catholics, and other factors brought Europe into an extended conflict which would result in heavy loss of life and destruction of entire regions. Holy Roman Emperors, including Ferdinand I, Maximillian II, Rudolf II and Matthias, had avoided war in the years leading up to 1618 by allowing different Christian faiths to spread without restraint inside the Empire. However, Matthias' successor, Ferdinand II, was a staunch Catholic who wanted to impose religious uniformity on his lands. This made him highly unpopular in Protestant Bohemia. The population's sentiments notwithstanding, the added insult of the nobility's rejection of Ferdinand, who had been elected Bohemian Crown Prince in 1617, triggered the Thirty Years' War.
In 1643, the Prince de Condé defeated the Spanish army at the Battle of Rocroi. This would lead to important negotiations and in turn to a series of treaties that would end the long war. In 1645, Condé defeated the Bavarian army at the second Battle of Nördlingen. Later, in 1648, the French army, led by Turenne and Condé, won another important battle at Zusmarshausen and Lens.
As one of history's greatest military commanders, the Prince de Condé helped France replace Spain as the dominant military force in Europe.
Sources: Wikipedia and Web Gallery of Art