Yang Yi is later expelled from the…

Sun Quan is still capable of making proper decisions at times, despite the deterioration in his previous clear thinking.

For example, when, as a sign of contempt, Wei's emperor Cao Rui offers him horses in exchange for pearls, jade, and tortoise shells in 235, Sun Quan ignores the implicit insult and makes the exchange, reasoning that his empire needs horses much more than pearls, jade, or tortoise shells.

The South Pointing Chariot is among the notable technological advances of this era.

A directional compass vehicle that actually has no magnetic function, it is operated by use of differential gears (which applies equal amount of torque to driving wheels rotating at different speeds).

It is because of this revolutionary device (and other achievements) that its inventor, engineer and government official Ma Jun, is known as one of the most brilliant mechanical engineers and inventors of his day (alongside Zhang Heng of the earlier Eastern Han Dynasty).

Considered by many to be as brilliant as his predecessor Zhang Heng, Ma Jun is in 235 the inventor of a hydraulic-powered, mechanical puppet theater designed for Emperor Ming of Wei (Cao Rui), and square-pallet chain pumps for irrigation of gardens in Luoyang.

Roman sources tell of larger campaigns east of the Rhine and north of the Danube during the third century, especially for the reigns of emperors Caracalla (in the year 213) and Maximinus Thrax (in the year 235).

While this has been known to historians for a long time, there was never any archaeological proof of any campaign during this time within the Germania Magna.

The sources are unclear on the extent of such military operations.

It was assumed that they took place near the Limes.

The few sources that suggested otherwise were assumed to be unreliable.

The Battle at the Harzhorn, as interpreted by the artifacts found to date, now proves that the Romans went far deeper into Germania during the third century than was thought possible earlier.

There is no explicit date for the battle.

A coin minted under and showing the portrait of emperor Commodus and some specific pieces of military equipment originally dated the battle to after 180.

A hypothesis suggested the early third century, such as the supposed Germanic campaigns of emperors Caracalla and Maximinus Thrax.

Both of these are attested in historical sources, but no archaeological proof had been found so far.

Later coinage finds depicting emperors Elagabal (218-222) and Severus Alexander (222-235) further suggests Maximinus Thrax's campaigns.

The Historia Augusta, a late Roman collection of biographies of the Roman Emperors, mentions that Maximinus Thrax marched north from Moguntiacum (today's Mainz) about three hundred (trecenta) to four hundred (quadringenta) Roman miles.

Since this was thought to be impossible, this passage was often changed to triginta and quadraginta (thirty to forty miles).

Numismatic Frank Berger dates the battle to between 230 and 235.

Germanic tribes had crossed the Rhine and devastated the Roman countryside in 233, in 235, Maximinus Thrax leads the revenge campaign into Germania, which had been prepared by his predecessor Severus Alexander.

The death of Alexander Severus, the last of the Syrian emperors, is considered as the end of the Principate system established by Augustus.

Although the Principate will continue in theory until the reign of Diocletian, Alexander's assassination signals the beginning of the chaotic period known as the Crisis of the Third Century, which will bring the empire to near collapse.

Hippolytus or Rome, who may be considered the first Antipope, has continued to attack his rivals in the Roman bishopric, Pope Urban I and Pope Pontian.

During Pontian’s pontificate, the schism of Hippolytus comes to an end.

Pontian and other church leaders (among them Hippolytus) are exiled by the emperor Maximinus Thrax to Sardinia, and in consequence of this sentence he resigns on September 25 or 28, 235.

It is unknown how long Pontian lived in exile: according to Liber Pontificalis he died due to the inhuman treatment and hardships he received in the Sardinian mines.

According to tradition, he died on the island of Tavolara.

Anterus, the son of Romulus, born in Petilia Policastro, succeeds Pontian as pope for only one month and ten days, creating one bishop for the city of Fondi.

The circumstance on the German frontier have driven the army to look for a new leader.

They choose Gaius Iulius Verus Maximinus, who is most likely of Thraco-Roman origin (believed so by Herodian in his writings).

According to the notoriously unreliable Augustan History (Historia Augusta), he was born in Thrace or Moesia to a Gothic father and an Alanic mother, an Iranian people of the Scythian-Sarmatian branch; this supposed parentage is however highly unlikely, as the presence of the Goths in the Danubian area is first attested after the beginning of the Crisis of the Third Century.

British historian Ronald Syme, writing that "the word 'Gothia' should have sufficed for condemnation" of the passage in the Augustan History, felt that the burden of evidence from Herodian, George Syncellus (an eighth century chronicler) and elsewhere pointed to Maximinus having been born in Moesia.

The references to his "Gothic" ancestry might refer to a Thracian Getae origin (the two populations were often confused by later writers, most notably by Jordanes in his Getica), as suggested by the paragraphs describing how "he was singularly beloved by the Getae, moreover, as if he were one of themselves" and how he spoke "almost pure Thracian".

His background is, in any case, that of a provincial of low birth, and is seen by the Senate as a barbarian, not even a true Roman, despite Caracalla’s edict granting citizenship to all freeborn inhabitants of the Empire.

Maximinus is similar in many ways to the later Thraco-Roman Roman emperors of the third to fifth century (Licinius, Galerius, Aureolus, Leo the Thracian, etc.), who elevate themselves, via a military career, from the condition of a common soldier in one of the Roman legions to the foremost positions of political power.

He had joined the army during the reign of Septimius Severus, but had not risen to a powerful position until promoted by Alexander Severus.

Maximinus had been given command of Legio IV Italica, composed of recruits from Pannonia, who are angered by Alexander's payments to the Alemanni and his avoidance of war.

The troops, among whom include the Legio XXII Primigenia, elect the stern Maximinus on either March 18 or March 19, 235, killing young Alexander and his mother at Moguntiacum (modern Mainz).

These assassinations secure the throne for Maximinus.

The Praetorian Guard acclaims him emperor, and their choice is grudgingly confirmed by the Senate, who are displeased to have a peasant as emperor.

Maximinus hates the nobility and is ruthless towards those he suspected of plotting against him.

He begins by eliminating the close advisors of Alexander.

His suspicions may have been justified; two plots against Maximinus are foiled.

The first is during a campaign across the Rhine, during which a group of officers, supported by influential senators, plot the destruction of a bridge across the river, then leave Maximinus stranded on the other side.

Afterward they plan to elect senator Magnus emperor; the plot is discovered, however, and the conspirators executed.

The second plot involves Mesopotamian archers, loyal to Alexander, who had planned to elevate Quartinus, but their leader Macedo changes sides and murders Quartinus instead, although this is not enough to save his own life.

The accession of Maximinus is commonly seen as the beginning of the Crisis of the Third Century (also known as the "Military Anarchy" or the "Imperial Crisis"), the commonly applied name for the crumbling and near collapse of the Roman Empire between 235 and 284 caused by three simultaneous crises: external invasion, internal civil war, and economic collapse.

Germanic tribes had crossed the Rhine and devastated the Roman countryside in 233.

In 235, Maximinus Thrax had led the revenge campaign into Germania, which had been prepared by his predecessor Severus Alexander, defeating a Germanic tribe beyond the Weser in the Battle at the Harzhorn.

The archaeologists responsible for the excavation of the battle site believe that the roughly fifteen hundred artifacts found at the battle site are associated with Roman legionaries.

Since Germanic tribes of the time were also sometimes equipped with Roman weaponry, one early assumption was that this could have been an inter-Germanic battle.

Other Germanic excavations of the time reveal that many such conflicts were fought during the third century.

The finding of many bolts associated with the Scorpio or Cheiroballistra, which were exclusively used by Roman legions, prove, according to the scientists involved, that this battle involved a larger number of Roman troops.

The working hypothesis of the scientists is that the Roman troops were on their way back from the North German Plain.

They found the Harzhorn pass blocked by a large number of Germans, and had to fight their way through, using their superior Roman artillery.

The finds indicate a Roman success, due to their superior military technology.

Maximinus, having secured the German frontier, at least for a while, sets up a winter encampment at Sirmium in Pannonia, and from that supply base fights the Dacians and the Sarmatians during the winter of 235–236.

Pope Anterus is thought to have been of Greek origin, but the name could indicate that he was a freed slave.

He is succeeded in 236 by Fabian.

Eusebius of Caesarea (Church History, VI.

29) relates how the Christians, having assembled in Rome to elect a new bishop, saw a dove alight upon the head of Fabian, a layman and stranger to the city, who was thus marked out for this dignity and was at once proclaimed bishop by acclamation, although there were several famous men among the candidates for the vacant position.

It is very probable that Hippolytus, before his death in Sardinia, he was reconciled to the other party at Rome, for, under Pope Fabian, his body and that of Pontian are brought to Rome.

Maximinus' first campaign is against the Alamanni, whom Maximinus defeats despite heavy Roman casualties in a swamp in the Agri Decumates.

After the victory, Maximinus takes the title Germanicus Maximus, raises his son Maximus to the rank of Caesar and Prince of Youths, and deifies his late wife Paulina.

Cao Rui had commenced large-scale palace and temple-building projects almost immediately after ascending the throne.

Part of it was to be expected—the Luoyang palaces had been remnants of the ones not destroyed by Dong Zhuo, and the temples were needed for the cults of his ancestors.

However, he has gone beyond the minimally required constructions, and continues to build temples and palaces throughout his reign, severely draining the imperial treasury.

While he occasionally halts projects at the officials' behest, the projects restart after brief breaks.

He not only builds palaces in Luoyang, but also builds a palace in Xuchang.

In 237, he further moves many of the magnificent statues and monuments that had been commissioned by Emperor Wu of Han from Chang'an to Luoyang, at great expenses and the cost of many lives.

He further builds gigantic bronze statues of his own and places them on a man-made hill inside his palace, surrounded by rare trees and plants and populated by rare animals.

Cao Rui is also increasing his collection of women, as his concubines and ladies-in-waiting number in the thousands.

His palace-building projects might have been with intent to house them.

In 237, he even orders that beautiful married women all be formally seized unless their husbands are able to ransom them, and that they will be married to soldiers instead—but that the most beautiful among them will become his concubines.

Despite some officials' protestations, this decree is apparently carried out, much to the distress of his people.

Despite his harem, however, Cao Rui is without any son who survives infancy.

He had adopted two sons to be his own—Cao Fang and Cao Xun, whom he had created princes in 235.

(It is usually accepted that they were sons of his cousins, although the exact parentage is not clear.)

In 237, Cao Rui takes the unprecedented (and unrepeated in Chinese history) action of setting his own temple name of Liezu and ordering that his temple never be torn down in the future.

(Based on Confucian regulations, except for the founder of the dynasty, rulers' temples are destroyed after six generations.)

He carries out these actions apparently in apprehension that he will be given an unflattering temple name (or none at all) and that his temple will eventually be destroyed, due to his lack of biological issue and unclear origin.

By 237, Cao Rui's favorite is no longer Empress Mao, but Consort Guo.

In this year, when Cao Rui is attending a feast hosted by Consort Guo, Consort Guo requests that Empress Mao be invited to join as well, but Cao Rui refuses and further orders that no news about the feast be given to Empress Mao.

However, the news leaks, and Empress Mao talks about the feast with him anyway.

He becomes exceedingly angry, and kills a number of his attendants whom he suspected of leaking the news to Empress Mao, and, inexplicably, orders Empress Mao to commit suicide, even though she is still buried with honors due an empress, and her family remains honored.