DUG-OUT, an underground chamber or passage dug out of a slope or bank or in a trench. The simplest form of dug-out is the small shelter for two or three men, protecting them rather against the elements than against the effects of enemy fire ; larger and more elaborate dug-outs will secure their occupants against bullets and splinters of shell ; while the deep mined works, constructed by all belligerents on the Western front during the World War, were capable of housing whole units in complete immunity from even the heaviest bombardment, and were in many cases equipped with lighting, sleeping and living facilities. As against this secu rity from shell fire, however, it was found that these large dug outs often proved traps for the garrisons sheltering in them, who were unable to emerge in time to repel a hostile infantry attack, and during the later years of the war their construction was largely discontinued. The word also designates the Western plain dwell ings of North American pioneers. (See also CANOE.) .DUGUAY-TROUIN, RENE (1673-1736), French sea captain, was born at St. Malo on June Io, 1673. On the outbreak of the war with England and Holland in 1689 he went to sea in a privateer owned by his family. As a volunteer in a vessel of 28 guns he was present in 1690 at a bloody combat with an English fleet of five merchant vessels. His family then gave him a corsair of 14 guns; and having been cast by a storm on the coast of Ire land, he burned two English ships in the River Limerick. In 1694 his vessel of 4o guns was captured by the English and he was con fined in the castle of Plymouth. He escaped and obtained com mand of a vessel of 48 guns and captured some English vessels on the Irish coast. In 1696 he made a brilliant capture of Dutch vessels and was made capitaine de fregate (commander) in the royal navy. In 1704-5 he persistently raided the coasts of Eng land. In 1706 he was raised to the rank of captain of a vessel of the line. In 1707 he captured off the Lizard the greater part of an English convoy of troops and munitions bound for Portugal. His most glorious action was the capture in 1711 of Rio Janeiro, on which he imposed a heavy contribution. In 1715 he was made chef d'escadre, and in 1728 lieutenant general des armees navales. He died in Paris on Sept. 27, 1736.
See his own Memoires (174o) ; and J. Poulain, Duguay-Trouin (1882).
In 1354 he was sent to England with the lords of Brittany to treat for the ransom of Charles of Blois, who had been defeated and captured by the English in 1347. When Rennes and Dinan were attacked by the duke of Lancaster in 1356, Du Guesclin fought continuously against the English, and at this time he en gaged in a celebrated duel with Sir Thomas Canterbury. He finally forced his way with provisions and reinforcements into Rennes, which he defended till June 1357, when the siege was raised in pursuance of the truce of Bordeaux. Shortly afterwards he passed into the service of France. In 1359, 136o, 1361 and 1362 he was continually in the field though he was twice a pris oner of the English. In May 1364 he defeated the Navarrese at Cocherel, and took the famous Captal de Buch prisoner. He had previously been made lord of Pontorson (1357), of La Roche Tesson (1361) and chamberlain (1364) ; he was now made count of Longueville and lieutenant of Normandy. Shortly afterwards Du Guesclin was taken prisoner by Sir John -Chandos at the battle of Auray, in which Charles of Blois was killed. Du Guesclin was ransomed for 1 oo,000 crowns, and was charged to lead the bands of discharged mercenaries, the famous compagnies, out of France. He marched with them into Spain, supported Henry of Trastamara against Pedro the Cruel, set the former upon the throne of Castile (1366), and was made constable of Castile and count of Trasta mara. In the following year he was defeated and captured by the Black Prince, ally of Pedro, at Navarete, but was soon released for a heavy ransom. Once more he fought for Henry, won the battle of Montiel (1369), reinstated him on the throne, and was created duke of Molinas.
In May 137o, at the command of Charles V., who named him constable of France, he returned to France. For nearly ten years he was engaged in fighting against the English in the south and the west of France, recovering from them the provinces of Poitou, Guienne and Auvergne. In 1373, when the duke of Brittany sought English aid against a threatened invasion by Charles V., Du Guesclin seized the duchy ; two years later he frustrated the attempt of the duke with an English army to recover it. In 1380 he was sent into Languedoc to suppress disturbances and brig andage, provoked by the harsh government of the duke of Anjou. His first act was to lay siege to the fortress of Chateauneuf Randon, but on the eve of its surrender the constable died on July 13, 1380.
See biography by D. F. Jamison (Charleston, 1863), which was translated into French (1866) by order of Marshal Count Randon, minister of war ; also S. Luce, Histoire de B. du Guesclin (1876, 3rd ed., 1896) .