"And he set up in the Forum an enormous column, to serve at once as a monument to himself and as a memorial of his work in the Forum. For that entire section had been hilly and he had cut it down for a distance equal to the height of the column, thus making the Forum level." (Cass.Dio 68.16.3)
With these words Cassius Dio describes more than a century later the building of the Forum Traiani and the erection of the Column of Trajan at that Forum. Unlike other monuments of Ancient Rome the Column survived to our days, probably because it was not only in Ancient times but also in the Medieval times one of the most significant symbols of Rome. Another reason for its survival might be a kind of ‘re-consecration’ under Pope Sixtus V. whereby a statue of Saint Peter was positioned at the top of the column.
However today the column of Trajan seems to be a single monument, but it is important to consider that it wasn’t planned to be a single standing monument in Ancient times. On the contrary the Column must be seen initially as part of a much greater whole, which served important practical purposes in the city of Rome.
Marcus Ulpius Traianus, Roman Emperor 98-117 AD, was the customer of that Forum. Trajan was born in about the around 54 AD in Spain, son of a Consul and hence a member of a noble Roman family. He showed such competency in public and especially military service that he was chosen by Nerva to be his successor on the Imperial throne. Trajan was formally adopted in 98 AD by Nerva, who died only a few months later. Only three years later Trajan got on the first of what were to be two large and difficult campaigns against the Dacian kingdom, rather civilized 'barbarians' who lived across the Danube in the area of what is now Romania. The Dacians were led by the skilful king Decebalus, who made the war difficult for the Romans. Since decades before the Trajanic wars the Dacians embodied a threat for the Roman Empire, from 85 to 86 AD the Dacians attacked the Roman province of Moesia, and in 87 AD, Domitian ordered a campaign against Dacia. The Roman general Cornelius Fuscus crossed the Danube into Dacia with 5 or 6 legions, but was heavily defeated at Tapae. In 88 AD, the Roman campaign continued, and the Roman army, this time under the command of Tettius Iulianus, defeated the Dacians at Tapae. After this battle, Decebal and Domitian reached peace. Following the peace treaty of 89 AD, Decebal became a client king of Rome’s mercy. Shortly after his succession Trajan decided to solve the Dacian problem once and forever, and he and his army were victorious at the end. Trajan returned to Rome to celebrate a triumph and to receive the award of the title Dacicus. But since the affairs in Dacia were not concluded by then Trajan returned to Dacia in 105 AD. This time the result of this new campaign was definite: Dacia was not only militarily defeated but also integrated into the Roman Empire as a new Roman province. Trajan also started further conquests later in his reign (for example the Parthian War 114-117 AD), but it was for the Dacian wars and his ensuing building projects in Rome that he is most remembered. Trajan returned to Rome with an immense quantity of booty, which he proceeded to spend mainly for buildings. The ultimate glory of Trajan's new Rome was undoubtedly the Forum Traiani, built out of colored, polished marble, bronze and gold.
We must consider therefore the immense importance of a Forum for the Roman citizens. From the earliest days of the city, the Forum Romanum had been the center of Roman business, trade and politics. Located at the base of the Palatine hill, the Forum Romanum was inflated over the years with temples, places of meeting and business, and various honorary statues of famous citizens. Here, politicians debated, citizens met, talked and voted, priests made sacrifices, and triumphant generals went through on their triumphal way to the Capitol. But soon at the beginning of the Imperial time the old Forum was no longer large enough to handle all the business which needed to be transacted. So some of the Emperors built new Fora to the north east of the old Forum, but still linked to it and to each other by doors and passages. Maybe Domitian started the construction on a fourth Imperial Forum, but could not finish it because of his premature assassination. So it was left to Trajan to fill the need for a new Forum. Trajan did more; however, than simply provide more space for the public business of Rome, he wanted to construct at the same time a monument to himself and to the glory of the Roman Empire. Again Cassius Dio is our source in telling that the whole was designed by Apollodorus, an architect who was employed by Trajan and the senate, not only in the construction of the forum, the basilica and maybe later of the temple, but his engineering abilities were best demonstrated in the bridge which he built over the Danube.
One of the features of the Forum Traiani, which was then built near the Quirinal hill, north of the Roman Forum and north-west of Augustus's Forum, was the Column. The enormous complex of the Forum consisted basically of a large open place, entered through a triumphal archway, in which the equestrian statue of the emperor stood in the center. Also part of the Forum was a great hall – the so-called Basilica Ulpia - , two library buildings which flanked the Column and the temple of the deified Trajan, built beyond the Column and libraries by his successor Hadrian.
 F.Coarelli. The Column of Trajan. Rome 2000. p.3
 D.Kleiner. Roman Sculpture. New Haven 1992.p.213.
 Cass.Dio 60.4 (… Apollodorus, the architect, who had built the various creations of Trajan in Rome - the forum, …)
 Amm. Marcell. 16.10.15 … verum cum ad Traiani forum venisset, singularem sub omni caelo structuram, ut opinamur, etiam numinum adsensione mirabilem, haerebat adtonitus per giganteos contextus circumferens mentem nec relatu effabiles nec rursus mortalibus adpetendos. omni itaque spe huius modi quicquam conandi depulsa Traiani equum solum locatum in atrii medio, qui ipsum principem vehit, imitari se velle dicebat et posse.
 J.E.Packer. The Forum of Trajan in Rome. Berkeley/Los Angeles/Oxford 1997. p.113