artpedia:

Jacques-Louis David - The Oath of the Horatii, 1784. Oil on canvas 

From the Musée du Louvre, Paris:

In the 7th century BC, the three Horatii brothers, chosen by the Romans to defy the Curiatii, the champions of the town of Alba, are swearing to defeat their enemies or die. As they receive their weapons from their father, the women of the family are prostrate with suffering. This painting, a royal commission, was the manifesto for a new style, neoclassicism. Both the architecture of the room and the poses of the warriors are rigorously geometrical.