Short answers, pulled from the story.
Roman engineers constructed Trajan's Column in the year 113 using twenty massive blocks of Carrara marble. Each block weighed approximately thirty-two tons while the final capital block at the top tipped the scales at fifty-three point three tons.
The continuous ribbon of sculpture winds around the shaft twenty-three times to show two thousand six hundred sixty-two figures across one hundred fifty-five distinct scenes. The narrative begins with the first campaign against the Dacians between 101 and 102 AD and continues with the second war fought from 105 to 106 AD.
Pope Sixtus V crowned the top of Trajan's Column with a bronze figure of Saint Peter on the 4th of December 1587. This replaced an earlier statue of Emperor Trajan that disappeared during the Middle Ages.
The Roman Senate voted to bury Trajan's ashes inside the square base of the column after he died in 117. His wife Plotina was interred there alongside him in golden urns which later disappeared from the monument.
Carol Twombly designed the typeface known as Trajan in 1989 using letter forms based on the specific inscription carved into the base. She worked from research conducted by Edward Catich regarding the original carving.