Marcus moves against the Quadi in 179-180,…

Emperor Ling creates Consort He as the new empress and makes her brother He Jin a key official in his government in 180.

(According to legends, she had initially been selected as an imperial consort because her family had bribed the eunuchs.)

She receives the empress position because she has given birth to Emperor Ling's son Liu Bian.

During the past few years, Emperor Ling has become interested in heavy spending to build imperial gardens, and to finance them he has ordered the prefectures and principalities to offer tributes to him personally.

This in turn has created pressures for officials to become corrupt.

However, he also listens to good advice at times, but does not follow his advisors consistently.

For the more honest of his officials, it has become a frustrating exercise to try to persuade Emperor Ling on points that are beneficial to the people—because he can in fact sometimes be persuaded, but not usually.

Evidence of Han-era mechanical engineering comes largely from the choice observational writings of sometimes disinterested Confucian scholars.

Professional artisan-engineers do not leave behind detailed records of their work.

Han scholars, who often have little or no expertise in mechanical engineering, sometimes provide insufficient information on the various technologies they describe.

Nevertheless, some Han literary sources provide crucial information.

For example, in 15 BCE the philosopher Yang Xiong described the invention of the belt drive for a quilling machine, which was of great importance to early textile manufacturing.

The inventions of the artisan-engineer Ding Huan are mentioned in the Miscellaneous Notes on the Western Capital.

Around 180 CE, Ding creates a manually operated rotary fan used for air conditioning within palace buildings.

Ding also uses gimbals as pivotal supports for one of his incense burners and invented the world's first known zoetrope lamp.

(Needham, Joseph.

[1986c].

Science and Civilisation in China: Volume 4, Physics and Physical Technology; Part 2, Mechanical Engineering.

Taipei: Caves Books Ltd) Modern archaeology has led to the discovery of Han artwork portraying inventions which are otherwise absent in Han literary sources.

As observed in Han miniature tomb models, but not in literary sources, the crank handle is used to operate the fans of winnowing machines that separate grain from chaff.

The odometer cart, invented during Han times, measures journey lengths, using mechanical figures banging drums and gongs to indicate each distance traveled.

This invention is depicted in Han artwork by the second century CE, yet detailed written descriptions are not offered until the third century CE.

Modern archaeologists have also unearthed specimens of devices used during the Han Dynasty, for example a pair of sliding metal calipers used by craftsmen for making minute measurements.

These calipers contain inscriptions of the exact day and year they were manufactured.

These tools are not mentioned in any Han literary sources.

Marcus Aurelius, a philosopher emperor, has lowered taxes and displayed charity toward the less fortunate.

He keeps, even during his campaigns against the Germans, a "spiritual diary," later known as the Meditations, which document his internal struggle to reconcile his Stoic philosophy of virtue and self-sacrifice with his role as a warrior-sovereign.

Marcus' Meditations offer a window on his inner life, but are largely undatable, and make few specific references to worldly affairs.

Marcus Aurelius has written the twelve books of the Meditations in Koine Greek as a source for his own guidance and self-improvement.

It is possible that large portions of the work were written at Sirmium, where he spends much time planning military campaigns from 170 to 180.

Some of it was written while he was positioned at Aquincum on campaign in Pannonia, because internal notes tell us that the second book was written when he was campaigning against the Quadi on the river Granova (modern-day Hron) and the third book was written at Carnuntum.

It is not clear that he ever intended the writings to be published, so the title Meditations is but one of several commonly assigned to the collection.

These writings take the form of quotations varying in length from one sentence to long paragraphs.

His stoic ideas often involve avoiding indulgence in sensory affections, a skill which, he says, will free a man from the pains and pleasures of the material world.

He claims that the only way a man can be harmed by others is to allow his reaction to overpower him.

An order or logos permeates existence.

Rationality and clearmindedness allow one to live in harmony with the logos.

This allows one to rise above faulty perceptions of "good" and "bad".

Having acquired the reputation of a philosopher king within his lifetime, the title will remain his after death; both Dio Cassius and the biographer call him "the philosopher".

Christians—Justin Martyr, Athenagoras, Melito—give him the title as well.

The emperor is immediately deified and his ashes are returned to Rome, and rest in Hadrian's mausoleum (modern Castel Sant'Angelo) until the Visigoth sack of the city in 410.

His campaigns against Germans and Sarmatians will also be commemorated by a column and a temple built in Rome.

Commodus has little interest in pursuing the war.

Against the advice of his senior generals, after negotiating a peace treaty with the Marcomanni and the Quadi, he leaves for Rome in early autumn 180, where he celebrates a triumph for the conclusion of the wars on October 22.

The Romans, under the command of Marcus Valerius Maximianus, fight and prevail against the Quadi in a decisive battle at Laugaricio (near modern Trenčín, Slovakia).

After the decisive victory in 178, the plan to annex Bohemia seems poised for success.

The death of Marcus Aurelius from plague while campaigning in 180, has left his son and heir Commodus with the unwinnable Danubian war and a treasury that has been seriously depleted by Marcus's wars and benevolences.

In a move that many Romans consider treasonable, Commodus abandons his father's military campaign against the German tribes and returns to Rome to ascend the imperial throne.

Marcus’s choice of Commodus as his successor, putting an end to the series of "adoptive emperors", will be highly criticized by later historians since Commodus was a political and military outsider, as well as an extreme egotist with neurotic problems.

Commodus devalues the Roman currency upon his accession, reducing the weight of the denarius from ninety-six per Roman pound to one hundred and five (3.85 grams to 3.35 grams).

He also reduces the silver purity from seventy-nine percent to seventy-six percent—the silver weight dropping from 2.57 grams to 2.34 grams.

Unlike the preceding Emperors Trajan, Hadrian, Antoninus Pius and Marcus Aurelius, Commodus seems to have had little interest in the business of administration and will tend throughout his reign to leave the practical running of the state to a succession of favorites, beginning at this time with Saoterus, a freedman from Nicomedia who had become his chamberlain.

Irenaeus, Bishop of Lugdunum in Gaul, writes a five-volume work in the second century, On the Detection and Overthrow of the So-Called Gnosis, today also called On the Detection and Overthrow of Knowledge Falsely So Called (Greek: lit. "Elenchus and Overturning of the Pseudonymous Knowledge"), commonly called Against Heresies (Latin: Adversus haereses).

The final phrase "of knowledge falsely so-called" (Greek: tes pseudonymou gnoseos genitive case; or nominative case pseudonymos gnosis) is a quotation of the apostle Paul's warning against "knowledge falsely so-called" in 1 Timothy 6:20.

Due to its reference to Eleutherus as the current bishop of Rome, the work is usually dated to about 180.

In it, Irenaeus identifies and describes several schools of gnosticism and contrasts their beliefs with what he describes as catholic, orthodox Christianity.

Only fragments of the original Greek text exist, but a complete copy exists in a wooden Latin translation, made shortly after its publication in Greek, and Books IV and V are also present in a literal Armenian translation.

Irenaeus’s purpose in writing Against Heresies is to refute the teachings of various Gnostic groups; apparently, several Greek merchants had begun an oratorial campaign praising the pursuit of "gnosis" in Irenaeus' bishopric.

Another popular theory states that a group of Gnostics known as the Valentinians remained part of the early Christian church, taking part in regular church celebrations despite their radical differences.

It is also said that Gnostics would secretly meet outside of regular church activity where they would discuss their "secret knowledge" and scripture that pertains to it.

As bishop, Irenaeus felt obligated to keep a close eye on the Valentinians and to safeguard the church from them.

In order to fulfill this duty, Irenaeus educated himself and became well informed of Gnostic doctrines and traditions.

This eventually led to the compilation of his treatise.

It appears however, that the main reason Irenaeus had taken on this work was because he felt that Christians in Asia and Phrygia especially need his protection from Gnostics, for they do not have as many bishops to oversee and help keep problems like this under control (probably only one bishop was assigned to a number of communities).

Therefore, due to the issue of distance between Irenaeus (who is in the western Roman province of Gaul) and the orthodox Christian community of Asia, Irenaeus finds that writing this treatise will be the best way to offer them guidance.

Against Heresies was the best surviving contemporary description of Gnosticism until the discovery of the Library of Nag Hammadi in 1945.

This publication is historically important as the dating of the publication is irrefutable and the document is among the earliest non-controversial confirming documentation for many of the sayings attributed by early Christian writers to Jesus and to the Letters of Paul.

Commodus has inherited many of his father's senior advisers, notably Tiberius Claudius Pompeianus (the second husband of Commodus's sister Lucilla), his father-in-law Gaius Bruttius Praesens, Titus Fundanius Vitrasius Pollio, and Aufidius Victorinus, who is Prefect of the City of Rome.

He also has five surviving sisters, all of them with husbands who are potential rivals.

Four of his sisters are considerably older than he; the eldest, Lucilla, holds the rank of Augusta as the widow of her first husband, Lucius Verus.

Operations continue against the Iazyges, the Buri and the so-called "free Dacians" living between the Danube and Roman Dacia.

Not much is known about this war, except that the Roman generals include Marcus Valerius Maximianus, and the future usurpers Pescennius Niger and Clodius Albinus.

At any rate, the victories they achieve are deemed sufficient for Commodus to claim the title "Germanicus Maximus" in mid-182.

The first crisis of Commodus’ reign comes in 182, when Lucilla engineers a conspiracy against her brother.

Her motive is alleged to have been envy of the Empress Crispina.

Her husband, Pompeianus, is not involved, but two men alleged to have been her lovers, Marcus Ummidius Quadratus Annianus (the consul of 167, who is also her first cousin) and Appius Claudius Quintianus, attempt to murder Commodus as he enters the theater.

They bungle the job and are seized by the emperor's bodyguard.

Quadratus and Quintianus ware executed; Lucilla is exiled to Capri and later killed.

Pompeianus retires from public life.

One of the two praetorian prefects, Tarrutenius Paternus, had actually been involved in the conspiracy but is not detected at this time, and in the aftermath, he and his colleague Sextus Tigidius Perennis are able to arrange for the murder of Saoterus, the hated chamberlain.

Commodus takes the loss of Saoterus badly, and Perennis now seizes the chance to advance himself by implicating Paternus in a second conspiracy, one apparently led by Publius Salvius Julianus, who is the son of the jurist Salvius Julianus and is betrothed to Paternus's daughter.

Salvius and Paternus are executed along with a number of other prominent consulars and senators.

Didius Julianus, the future emperor, a relative of Salvius Julianus, is dismissed from the governorship of Germania Inferior.

Perennis takes over the reins of government and Commodus finds a new chamberlain and favorite in Cleander, a Phrygian freedman who had married one of the emperor's mistresses, Demostratia.

Cleander is in fact the person who had murdered Saoterus.

After these attempts on his life, Commodus spends much of his time outside Rome, mostly on the family estates at Lanuvium.

Physically strong, his chief interest is in sport: taking part in horse racing, chariot racing, and combats with beasts and men, mostly in private but also on occasion in public.