Designed by the architect Apollodorus of Damascus, the column originally supported a statue of Trajan, which was later replaced with a statue of Saint Peter in 1587 CE. It is part of Trajan's Forum, serving both as a propaganda tool celebrating Roman military prowess and as Trajan's tomb, with his ashes reportedly placed in a chamber at its base. The column remains one of the most well-preserved and studied examples of Roman narrative relief sculpture.

circa 112 CE

The structure is about 30 metres (98 feet) in height, 35 metres (115 feet) including its large pedestal. The shaft is made from a series of 20 colossal Carrara marble[a] drums, each weighing about 32 tons, with a diameter of 3.7 metres (12.1 feet). The 190-metre (620-foot) frieze winds around the shaft 23 times. Inside the shaft, a spiral staircase of 185 steps provides access to a viewing deck at the top. The capital block of Trajan's Column weighs 53.3 tons, and had to be lifted to a height of about 34 metres (112 feet). Ancient coins indicate preliminary plans to top the column with a statue of a bird, probably an eagle. After construction, a statue of Trajan was put in place; this disappeared in the Middle Ages. On December 4, 1587, the top was crowned with a bronze figure of Saint Peter the Apostle by Pope Sixtus V, which remains to this day.

The column shows 2,662 figures and 155 scenes; Trajan himself appears on the column 58 times. The continuous helical frieze winds 23 times from base to capital and was an architectural innovation in its time. The design was adopted by later emperors such as Marcus Aurelius. The narrative band expands from about 1 metre (3.3 feet) at the base of the column to 1.2 metres (3.9 feet) at the top. The scenes unfold continuously. Often a variety of different perspectives are used in the same scene, so that more can be revealed (e.g., a different angle is used to show men working behind a wall).

circa 112 CE

The relief on Trajan's Column illustrates the two Dacian campaigns, with the lower half depicting the first war (101–102 CE) and the upper half illustrating the second (105–106 CE). Rather than emphasizing combat, the frieze focuses on structured military activities, including imperial addresses (adlocutio), ritual sacrifices (lustratio), and the army's departure for campaign (profectio). Depictions of actual battle scenes are relatively scarce; instead, the relief portrays disciplined soldiers engaged in ceremony, construction, and engineering work, reinforcing the idea that the Dacian campaigns were strategic rather than purely violent.

The imagery suggests that the intent was to integrate Dacia into the Roman Empire rather than merely to destroy it. Notably, scenes of violence against women and children are absent, a rare choice in Roman military art. Some scholars propose that the focus on order and construction was designed to reassure the Roman populace, presenting the army as disciplined rather than destructive. Others suggest that the frequent depictions of tree-felling (48 out of 224 trees on the column) and the bridging of the Danube symbolize a total conquest and transformation of the Dacian landscape.

Key moments captured in the relief include:

• The first crossing of the Danube by Roman legions
• Trajan's voyage up the Danube
• The Dacians’ surrender at the end of the first war
• The great sacrifice at the Danube bridge during the second war
• The siege of the Dacian capital
• The death of King Decebalus

A winged personification of Victory, writing on a shield, divides the two campaign narratives, flanked by military trophies.

The column meticulously distinguishes between Romans and Dacians, as well as different social and military ranks. The frieze features approximately 2,500 figures, including sailors, soldiers, statesmen, and priests, offering valuable insights into Roman and barbarian weaponry, armor, and military engineering. Notable details include depictions of ballistae and catapults, as well as 37 distinct tree types, some of which scholars have attempted to identify botanically. The artistic precision reinforces a sense of realism, presenting the images as a historical record rather than mere propaganda.

The emperor Trajan appears 58 times, always as the central figure among his troops, reinforcing his leadership and divine favor. Although women are rare in Roman state art, they appear in the margins of several scenes on the column. Roman depictions of warfare often use women as symbols of subjugation, reinforcing the narrative of conquest. However, one particular scene stands out as one of the most unusual and violent depictions of women in Roman art—a depiction of four Dacian women torturing two naked men. This unsettling moment contrasts with the otherwise restrained portrayal of warfare, highlighting the Romans’ perception of their enemies as both noble and barbaric.