Damnatio memoriae

Damnatio memoriae is a modern Latin phrase meaning "condemnation of memory", indicating that a person is to be excluded from official accounts. There are and have been many routes to damnatio memoriae, including the destruction of depictions, the removal of names from inscriptions and documents, and even large-scale rewritings of history. The term can be applied to other instances of official scrubbing; the practice is seen as long ago as the aftermath of the reign of the Egyptian Pharaohs Akhenaten in the 13th century BC, and Hatshepsut in the 14th century BC.
Etymology.
Although the term "damnatio memoriae" is Latin, the phrase was not used by the ancient Romans, and first appeared in a dissertation written in Germany in 1689. The term is used in modern scholarship to cover a wide array of official and unofficial sanctions through which the physical remnants and memories of a deceased individual are destroyed.
Practice.
By design, evidence of this practice is scarce. One example of "damnatio memoriae", or oblivion, as a punishment was meted out by the peoples of Ephesus after Herostratus set fire to the Temple of Artemis, one of the Seven Wonders of antiquity. Felons would be erased from history for the crimes they had committed.
Egyptians also practiced this, as seen in relics from Akhenaten’s tomb and elsewhere. His worship restricted to the one god Aten instead of the many gods common to the time was considered heretical. During his reign, Akhenaten himself attempted to have all references to the god Amun chipped away, to stop the worship of that god. After his reign, temples to the Aten were dismantled and the stones reused to create other temples. Images of Akhenaten had their faces chipped away, and images and references to Amun reappeared. The people blamed their misfortunes on Akhenaten's shift of worship to Atenism, away from the gods they served before him.
The sense of the expression "damnatio memoriae" and of the sanction is to remove every trace of the person from life, as if they had never existed, in order to preserve the honour of the city. In a city that stressed social appearance, respectability, and the pride of being a true Roman as a fundamental requirement of the citizen, it was perhaps the severest punishment.
In ancient Roman society, "a Roman's house was perceived as an extension of the self, signalling to divine protectors and social and genealogical status to the world outside." Similarly, just as the domus would have been seen as an extension of the self, memory was thought of as one of the best ways to understand the self. In a society without much written documentation, memory training was a big part of Roman education. Orators, leaders, and poets alike used memory training devices or memory palaces to help give speeches or tell long epic poems. In "The Natural History," Pliny writes:It would be far from easy to pronounce what person has been the most remarkable for the excellence of his memory, that blessing so essential for the enjoyment of life, there being so many that were celebrated for it. King Cyrus knew all the soldiers of his army by name: L. Scipio the names of all the Roman people.
Memory palaces provided an aid for remembering certain key ideas. By assigning locations in their homes for different ideas, poets or the like could walk back and forth through their house, recalling ideas with every step. Memory training often involved assigning ideas to wall paintings, floor mosaics, and sculptures that adorned many ancient Roman homes. The punishment of "damnatio memoriae" involved altering the rooms, many times destroying or tampering with the art in their homes as well, so the house would no longer be identifiable as the perpetrator's home. This would in turn, erase the perpetrator's very existence. 
In ancient Rome, the practice of "damnatio memoriae" was the condemnation of Roman elites and emperors after their deaths. If the senate or a later emperor did not like the acts of an individual, they could have his property seized, his name erased and his statues reworked. Because there is an economic incentive to seize property and rework statues, historians and archaeologists have had difficulty determining when official "damnatio memoriae" actually took place, although it seems to have been quite rare.
Compounding this difficulty is the fact that a completely successful "damnatio memoriae" results—by definition—in the full and total erasure of the subject from the historical record. In actual practice however it is unlikely that such complete success was possible except in cases where the individual in question was of limited contemporary notability, as even comprehensive obliteration of the person's existence and actions in records and the like would continue to be historically visible without extensive reworking. The impracticality of such a cover-up could be vast—in the case of Emperor Geta, for example, it appears that coins bearing his effigy continued to circulate for years after his condemnation, even though the mere mention of his name was punishable by death.
Difficulties in implementation also arose if there was not full and enduring agreement with the punishment, such as when the senate's condemnation of Nero was implemented—leading to attacks on many of his statues—but subsequently evaded with the enormous funeral he was given by Vitellius. Similarly, there was little to prevent historians later "resurrecting" the memory of the sanctioned person.
In the Middle Ages, heresiarchs could have their memory condemned. The Council of Constance decreed the "damnatio memoriae" of John Wycliffe.
Modern usage.
While extreme "damnatio memoriae" is not carried out in modern times—naming or writing about a person fallen from favour is not subject to formal punishment—less total examples of "damnatio memoriae" in modern times include the removal of statues of Stalin and other Communist leaders in the former Soviet Union. Following a 2015 decision, Ukraine successfully dismantled all 1,320 statues of Lenin after its independence, as well as renaming roads and structures named under Soviet authority.
In the United States, the monument for the Battle of Saratoga has a blank niche where Benedict Arnold's name is missing from the list of victorious generals. Various other Revolutionary War monuments either omit his name or, in the case of West Point, anonymously list only his rank and date of birth. 
The treatment of Chinese politician Zhao Ziyang following his fall from grace inside the Chinese Communist Party is regarded as a modern case of "damnatio memoriae".
Analysis.
Looking at cases of "damnatio memoriae" in modern Irish history, Guy Beiner has argued that iconoclastic vandalism only makes martyrs of the "dishonored," thus ensuring that they'll be remembered for all time. Nonetheless, Beiner goes on to argue that the purpose of "damnatio memoriae"—rather than being to erase people from history—was to guarantee only negative memories of those who were so dishonored. Charles Hedrick therefore proposes that a distinction be made between "damnatio memoriae" (the condemnation of a deceased person) and "abolitio memoriae" (the actual erasure of another from historical texts).