of this military ensign on the Danubian plaques is explained simply as due to chance — the result of a fortuitous combination of horseman and sky-god themes through the imagination of native sculptors. Trajan's Column in Rome On Trajan's Column (113 AD), Dacian soldiers are represented carrying a draco in 20 scenes. One depicts the draco borne by Dacian cavalry crossing the Danube by swimming with their horses. In another, the draco is planted in the center of a Dacian citadel and surrounded by the skulls of several Roman prisoners. On Trajan's Column the draco is the symbolic image of victory although it is absent from pictures on the column that illustrate Trajan's second war against the Dacians, when the Romans conquered about 18 ℅ of Dacia territories in quest for gold to pay their legions . Roman coins of Dacia The draco appears on coins of Roman Emperor Antoninus Pius (r.138–161 AD), indicating that it was still the characteristic emblem in the 2nd century. In AD 250 on a coin of Decius the Roman province of Dacia holds a wolf- or hound-dragon standard. The same type also occurs on antoniniani coins of Claudius Gothicus (r.268–270) and Aurelian (r.270–275). Arch of Galerius in Thessaloniki The characteristic Dacian dragon emblem is carried by a group of Dacian horsemen depicted on the Arch of Galerius and Rotunda in Thessaloniki, Greece. Funerary sculptured monument of Chester A draco (considered in 1955 by R. P. Wright of Dacian or Sarmatian type) is depicted on a large stone found at Deva Victrix (Chester, UK) in the North Wall (West) in 1890. The dragon flag is represented horizontally, as held by the cavalryman but its head is not visible, because the stone is rather deteriorated. Most scholars consider the horseman is a Sarmatian, wearing a Sarmatian helmet and carrying a Sarmatian standard. According to Mihăilescu-Bîrliba (2009) the depiction of the Dacian standard is certain and similar representations can be observed on the most important monuments of the Roman triumph over Dacians. A military diploma (dated to 146 AD) found at Chester mentions among the units of the released soldiers the name of cohors I Aelia Dacorum. Therefore, the horseman depicted on the tombstone at Chester could be a Dacian cavalryman, belonging to a vexillatio of cohors I Aelia Dacorum. P. A. Holder suggest that the cohort was created in 102 or a little earlier, with Dacians