You're looking at the inscription from Trajan's Column, circa 113 A.D.. The person who engraved these letters, the Senate and the People of Rome who dedicated them, and Trajan himself are long since dust. But the words remain.
This particular set of characters happens to be the basis of modern typography: an unintended consequence, but true. Typesetters have long considered Trajan's column to be the gold standard of Roman capital letters. Every printed word in a Western language owes a little something to this bit of Second Century political adulation.
Which goes to show the persistence and power of words -- or, in this case, the mere form of words. This inscription was meant to immortalize a certain Marcus Ulpius Nerva Traianus for his victory in the otherwise-forgotten Dacian Wars. Instead, it really came to immortalize an idea: one of classical beauty, of the delicate serifs and contrasting strokes which still support the alphabet you are now reading. It's a legacy far greater than quelling some upstart empire on the banks of the Danube.
In our increasingly twitterized world, it's easy to forget the value of words. "Less is more," as communication gets stripped to its barest essentials. Syntax, elegance, and grammar -- all gone, in the service of utilitarian economy.
But just because we're no longer chipping our thoughts into stone, we shouldn't assume their lack of permanence or effect. Our most trivial online musings rarely escape the unblinking, restless gaze of Google and its seemingly limitless virtual libraries of digital storage. It would be fascinating to peer 19 centuries into the future, squinting like some bygone artisan under a hot Roman sun, to see what of our words remain for others. Surely there will be unintended consequences.