Montargis, a town of France, in the department of Loiret, on the left bank of the Loing, and at the junction of the canals of Briare, Orleans, and the Loing, connecting the navigation of the Seine and the Loire, 62 m. S. by E. of Paris, and 40 m. E. by N. of Orleans; pop. in 1866, 7,757. The town is well built on a plain which extends from the river to the neighboring forest of Montargis; and it has an active trade, chiefly in grain, wax, honey, and agricultural products. It has also considerable manufactories of cotton goods, cutlery, paper, etc. The most interesting building is the ruin of the once extensive castle of Montargis, on a hill near the town. This was built by Charles V. (1364-'80), and was very strongly fortified, with accommodations for an unusually large garrison. The great hall of the castle (55 by 184 ft.) was elaborately decorated. Among its ornaments was a carving of the combat of a dog and an accused murderer, which tradition represents as having taken place at Paris in 1371, in accordance with the custom of the ordeal of battle then in vogue. The dog having overcome in the combat the alleged murderer of his master, the criminal confessed his crime and was executed.

From the carving, this story became universally known as that of the "dog of Montargis".