Almost no paint covers this vast canvas. Nude figures drawn in chalk and ink throw up their arms, embrace and reach out to one another, and only a few heads are finished in color. The deputies of France's Third Estate are swearing an oath, but the picture never got further than this stage. The scene is June 20, 1789, when the deputies pledged not to separate until they had given the kingdom a constitution.

Jacques-Louis David was not there, but he persuaded the Jacobins and then the National Assembly to back his plan to show it. The canvas, about 23 by 34 feet (7.15 × 10.40 m), was meant to decorate a wall of the Assembly's chamber, but for political and financial reasons it stayed a sketch. Versailles notes that even unfinished it shows a new way of painting history, setting a scene from the present in the classical tradition. David showed a finished drawing of the composition at the Salon of 1791, a separate work.

The unfinished canvas, dated 1791–92, is at the Palace of Versailles.