Rome, Italy | Rome has given birth to an ambitious "vanishing" artwork with William Kentridge's completion of a giant frieze of the city's "heroic and shameful" history that he has stencilled out of the dirt caking an embankment of the Tiber.

The South African artist's idiosyncratic take on the Eternal City's defining moments is a 10-metre-tall(33-feet) mural that, following completion this week, now lines a 550-metre (1,800-feet) stretch of the famous river.

The artist told AFP he does not expect his "Triumphs and Laments" to last more than five years before the blackening impact of pollution results in its epic images vanishing from view.

"It is an ephemeral project because that is the nature of it," Kentridge, 60, said in an interview ahead of the work's official inauguration on April 21.

"It is making a drawing by erasing the dirt on the wall, not by adding anything to it.

"The wall starts off black and then you wash around the drawings and what is left is the image in the rock.

"After four or five years the rock will get dirty again from pollution and from growth. So the rock will come out and meet and swallow the image with its own darkness."

- Remembered and forgotten -While providing a living example of the impact of environmental degradation, the work is also a commentary on the flawed nature of memory, both individual and collective, Kentridge said.

"There are things we should hold on to but forget. And historical memories, things that society should remember, that get forgotten.

"Every history has a mixture of the heroic and the shameful, of glory and shame, and that is what the piece is about."

An example of how this overarching theme is addressed is Kentridge's juxtaposition of the glories of the renaissance, most spectacularly represented in Rome by the construction of St Peter's basilica, with the contemporaneous confinement of Jews to the city's ghetto.

The papal bull creating the ghetto was issued in 1555, half a century after work started on St Peter's.

"So this heroic history and this shameful history are right together," Kentridge said. "I always though the ghetto was a medieval project, I had not realised the great moments of Roman art from the 16th Century were at the same time as that."

The mural contains sections inspired by prehistoric times and by mythology alongside figures from recent history, including the film director Pier Paolo Passolini and film stars Marcello Mastroianni and Anita Ekberg, symbols of the "Dolce Vita" of 1960s Rome.

It does not follow a chronological structure.

A reference to the current migrant crisis and mass drownings of asylum-seekers off Italy's southern shores is made in the form of a depiction of a Roman slave galley.

A depiction of Cicero, the famous orator of ancient Rome, is followed by one of Benito Mussolini that Kentridge revealed had been inspired by a fresco of the fascist dictator that still exists in Naples.

- Neglected waterfront -Cicero appears again after Mussolini, only this time the staunch defender of the constitutional principles of the Roman republic is depicted as a shattered figure.

In similar vein, heroic military figures from the Emperor Marcus Aurelius onwards are all shown with cracks as a representation of the hubris that has marked the high points of the city's history, preceding inevitable collapse.

Kenridge said he had worked with a team of researchers to identify historic images he could use as the basis for his drawings, whittling down a list of 500 possibles to 50.

"In the end it was an idiosyncratic, personal choice," he said.

The project, the brainchild of a non-profit organisation dedicated to the renovation of Rome's neglected waterfront, has been a long time in the making.

Kenridge first saw the site 15 years ago and completed his first sketches in 2011 before the project fell foul of Italy's notorious bureacracy.

"The drawings were one job but the really hard part was getting the permissions," he said. "That was four years hard slog."

The mural is located on the right bank of the Tiber in the Trastevere district of Rome, close to St Peter's and across the water from the Ghetto area.