The Column of Trajan tells the story of Trajan's victory against the Dacians.  Over 128 feet high, the narrative wraps around the entirety of the column and tells the story over 625 feet of marble.  As a result, the compositions are crowded and the entire story is difficult to view in its entirety.

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The defeated Dacians are depicted on the base of the column. They are shown as being worthy opponents to further highlight how significant the victory was for Trajan -- they appear strong, which shows how strong Trajan's army needed to be to defeat them. Above the defeated Dacians is a victory laurel to again highlight the significance of winning the battle against them.

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Originally, two libraries stood next to the column. Each had manuscripts detailing the Roman-Dacian war. One had the manuscripts in Roman, and the other in Greek. (Lamassu guardians are associated with Assyrian architecture and art, and steles, such as the Stele of Hammurabi, are associated with the Babylonians.)

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Ancient Greek and Roman architecture can be broken down into three main chronological groupings, from oldest to youngest: the Doric, the Ionic, and the Corinthian. As a building of the Roman Empire, the Pantheon, built between 27 BCE and 126 CE, is emblematic of the Corinthian order, especially its ornate columns lining its portico.

The three "classical orders" applied to columns in Ancient Greek architecture are Doric, Ionian, and Corinthian, going from least to most ornate. The Ionic column is most easily distinguished by its capital, or the top of the column. On every Ionic column, a scroll-shaped ornamentation is placed at the top portion of the column.

Often found in Ancient Greek architecture, female figures used as part of or in place of plainer columns are known as caryatids.

Columns in the Doric order sit directly on the stylobate without a base. The other two Classical Greek orders, Ionic and Corinthian, both employ bases.

Tuscan columns are the standard type of Etruscan column. They closely resemble Doric columns, but are usually made of wood, have a base and are not fluted along the shaft.

The "cella" is the central room or chamber of an ancient temple; often this is where the cult statue of the god or goddess would be set up.

In Greek and Roman architecture, a circular building is called a tholos. The tholos (plu. tholoi) is more common in Greek architecture than in Roman architecture; normally they were used for circular temples or shrines. In the Mycenaean tradition, the term "tholos" refers to a kind of circular, beehive-shaped tomb.