Roman Empire

Augustus of Prima Porta: Created around 15 CE in Rome, this statue depicts the first Roman Emperor Octavius Augustus.  As was custom of the Roman rulers, they glorified their own images in order to assume divinity and direct descent from the gods themselves, a common technique that strengthened their legitimacy to rule. Augustus associated himself as direct descendant form Aeneas, a Trojan prince who was supposedly from the same lineage as Romulus and Remus. While he is portrayed as giving a speech in the above image, many other characteristics define him as this god-like Roman; the breastplates emphasize his image with the god Apollo and his bare feet say that he is extremely divine and have walked sacred places (can't get those godly feet dirty on any old Roman road!) All of this is very important to keep in mind when learning about any Roman ruler; because they believed themselves directed by the gods and goddesses of their religion, this affected how they ruled and the decisions they made throughout the course of the Roman Empire.
Source: http://pal.loswego.k12.or.us/art_lit/Rome-VolunteerPresentation-Notes.pdf

Arch of Constantine I: Erected in 315 CE under Constantine I's rule, this famous arch was aptly named for its commemoration of Constantine I's victory over Roman tyrant Maxentius. This has not only made it the largest surviving triumphal arch, but also one of the last impressive pieces of architecture created at all in Rome. The arch was also prominent in political propaganda for Constantine I, to renown him amongst all the other great Roman emperors for governing his people well and taking successful military action. Made of three separate marble arches and other minor more colorful arches, many of the statues and reliefs found on the Arch are visuals of godly figures such as Diana, Hercules, and Constantine being crowned by Victory (or Nike), which, once again emphasizes the religious aspects that were demanded to maintain a strong ruling through the ruler himself.
Source: http://www.ancient.eu/article/497/

Aqueduct of Segovia: Built during the second half of the 1st century CE, its one of the most unique and well preserved aqueducts in Roman architecture. Not only is the technological advancement of it, the sheer size (about 14 kilometers), the beautiful arches amazing, it also moves through hills and and valleys. Politically this is a very important artifact (I guess you could call it that, in a sense), mainly because aqueducts are the one testimony of Roman society that concludes whether the armies were victorious in their wars/ if the Roman ruler was cut out for ruling in the first place.
Source: https://www.wmf.org/project/aqueduct-segovia
http://whc.unesco.org/en/list/311

Vindolanda Tablets: These tablets are very unique, mainly because they're one of the oldest handwritten artifacts discovered from Roman Britain, enscribed on wooden tablets rather than the common papyrus; also they contain the most important military and private messages concerning the northern front at the Roman fort of Vindolanda. They are believed to be from around the 1st to 2nd century CE. Interestingly enough, more than 750 tablets have been translated from the cursive Latin script into messages passed from wealthy families, slaves, corresponding to private military matters, trading, other businesses, and the most popular, a birthday party invitation written by Claudia Severa, a commander's wife to another woman at another fort; it's considered the earliest examples of Latin written by a woman in the Roman Empire.
Source: https://en.wikipedia.org/wiki/Vindolanda_tablets (oh, how we love wikipedia)

The Basilica Papale di San Pietro: The site of the Basilica has always held some kind of church since the rule of Constantine the Great 272 CE. This particular church was constructed around 1506-1626 CE, is considered one of the most defining architectural feats of the Renaissance era and has gained namesake as the holiest Catholic shrine in Christendom. Because it's believed that St. Peters was the first Pope and Bishop of Rome, the Basilica Papale di San Pietro, or St. Peter's Basilica of the Vatican was actually named after him; also, the belief that his tomb rests within the monument, it's become a tradition for new Popes to be entered into their positions at this particular setting. Because of its special liturgical elements (a specific form of worship through a religion's traditions, etc.) St. Peter's Basilica is a very common pilgrimage.
Source: https://en.wikipedia.org/wiki/St._Peter%27s_Basilica

The Pantheon of Hadrian: Built by Hadrian, the fourteenth emperor of Rome in 125 CE, the Pantheon was actually rebuilt upon the foundations of two past Pantheons constructed by two earlier emperors. Both Pantheons oddly either burned down or was struck by lightning and then burned down. This Pantheon is known as one of the best preserved buildings of the Roman Empire; its dome once again emphasizes their strength in building beautiful things. The Pantheon of Hadrian is believed to have been a temple, or more realistically, a possible place where the emperor [Hadrian] could appear before his people and remind them of his divinity and ultimate rule. We also know that Hadrian dedicated the Pantheon to the Greek gods, especially as its structure is the epitome of Greek belief (the wide spaces, multiple levels inside, and the Greek, rather than Latin name, Pantheon) But, unsurprisingly, whatever it had once been used for didn't last very long; by 608 CE, the Pantheon had been converted into the church of St. Mary of the Martyrs, and two bell towers were later added on. Once again, we can get a glimpse of the political aspects of the ruling emperors, and the style in which they proclaimed their legitimacy.
Source: http://www.ancient.eu/Pantheon/
http://www.oneonta.edu/faculty/farberas/arth/arth200/politics/roman_architecture.html

Basilica Ulpia: Completed around 112 CE, this structure is part of the Trajan Forum. After the Roman Emperor Trajan conquered Dacia in 106 CE, he brought the architect, Appollodorus with him to create a forum that represented his rule and would make others remember him. The scale of the overall forum is massive, surprising even the later emperor, Constantine II. Basilica Ulpia is actually the second name of Trajan, lavishly built with beautiful reliefs, marble, floors, and geometric patterns. It is part of one of the largest Roman forums to be constructed.
Source: http://famouswonders.com/forum-of-trajan/
http://www.aviewoncities.com/rome/forumoftrajan.htm

Arch of Titus: This is actually one of the most famous Triumphal arches (arches that commemorate victories in war/conquest, etc.), constructed for the current Roman emperor, Domitian in 81 CE for his father, Vespacian, and brother, Titus, during their plunder of Jerusalem during the Jewish War of Judea around 70-71 CE. It's artistry clearly states the divinity of its commemorated emperors: there are panels that depict the scene of Titus himself sacking Jerusalem and riding in chariots led by Victory and Roma, a woman who took on a journey with the ancient Romulus and Remus. The Roman art is also a feat within itself, as it really represents its growth through the course of the empire's history and "the illusion of space."
Source: http://www.ancient.eu/article/499/

Forum of Trajan: This forum (that also includes the Basilica Ulpia) was created to surpass all expectations of any other Roman architecture standing at the time. Reiterated, the architect, Appollodorus, was brought in to create this commemoration; the Forum consists of a large public square, with several colonades, closed in on one side by the Basilica Ulpia and containing two large libraries. Several arches emphasize the Roman style in architecture, as well as the statue of Trajan, courtyards, etc. It was used commonly for public ceremonies for a ruler to challenge his own country; for example, in 118 CE, "Adriano publicly burned tables with citizen's debts in the piazza, as a statement to the treasury." The libraries are believed to have been used to host poetry readings, court hearings for slaves in the Basilica, but most of all, the Forum of Trajan was a message for Roman imperial propaganda
Source: http://penelope.uchicago.edu/~grout/encyclopaedia_romana/imperialfora/trajan/forumtrajani.html
http://www.capitolium.org/eng/fori/traiano.htm

Polybius Text: Polybius is someone every student should learn about. Born in 213 BCE in Arcadia, Greece, he became good friends with Scipio (one of the greatest generals of all time) who recruited Polybius as his closest advisor concerning political and military matters. Traveling across the Mediterranean, he experienced the expansion of Rome, through military conquests. His writing is most curious, in that it's probably one of the most reliable pieces of writing from about Rome, since Polybius hardly believed in using myths and legends to tell of his experiences of the constitution of Rome, the sequence of its conquests, and focused not a variety of different peoples and regions, a more universal history than most one-side historians at the time. He also proposed his own theory on the constant cycle of ruling civilizations, from king to tyranny, etc. and wrote about his own beliefs in the separation of powers, later laying the sketch of the U.S constitution. If you're interested in reading more specifically what he wrote, the entire translated version of Polybius's work is in the link below :)
Source: http://www.humanistictexts.org/polybius.htm