As Michelangelo was to Pope Julius II, and Bernini to Cardinal Scipione Borghese, so was Pietro Cascella to Silvio Berlusconi. Neither was perhaps in the same league as their predecessors as artist and patron respectively, but despite his many public monuments, notably that at Auschwitz, Cascella is most likely to be remembered for having sculpted the Italian Prime Minister’s colossal private mausoleum.

Rising 8m above the ground, and plunging 5m under it, the edifice was built in 1993 from 100 tonnes of white marble at Berlusconi’s villa on the outskirts of Milan. Cascella had known the entrepreneur since his earliest days as a businessman in the 1960s, when he had commissioned pieces from the artist for the public spaces of the property developments on which his fortune was founded.

After the death of his father in 1989 Berlusconi asked Cascella to design a family tomb, “but not one with skulls all over it”. Cascella obliged with a characteristically massive work, crowned with the geometric forms of spheres, discs and pyramids typical of his sculptures. It represented the celestial vault, he said, “where we all come from, and to where we all return”.

The select few who have seen inside — among the first were the Gorbachevs — have reported that there is a pharaonic sarcophagus for Berlusconi himself, together with 36 niches for family and close friends. In 2004, towards the end of his second premiership, Berlusconi’s Government repealed an inconvenient law that prohibited burial of human remains other than in designated cemeteries.

Nonetheless, Berlusconi’s parents are both buried in the family crypt in Milan itself. Cascella, however, had made provision that should he choose in time to repose in his own memorial, Italy’s richest man will have to hand all the necessities of the next life: a bas-relief depicts fruit, bread and a mobile telephone.

Pietro Cascella was born at Pescara in 1921. The chief influence on his becoming an artist was his grandfather, a noted illustrator and engraver, but both his uncle and his father (a close friend of the poet and nationalist Gabriele D’Annunzio) were also painters.

In 1938 Cascella moved to Rome to study at its Academy of Fine Art, and at 22 he exhibited in the city’s quadrennial show. At the end of the war he opened a small studio with his first wife, Anna Maria Cesarini, and his elder brother Andrea, with whom he was to collaborate frequently.

Until the mid-1950s Cascella worked principally as a ceramicist and as a painter. A key commission was that to decorate a 185 sq m ceiling at the Farnesina, the Italian Foreign Office in Rome. He credited this with helping him to appreciate the relationship between architecture and sculpture. He showed his ceramics at the Venice Biennale in 1948, and in each of the next three decades, but anticipating his move towards sculpture these pieces were gradually changing from richly coloured forms to pared-down works in monochrome.

The turning point in his career came when he and his brother and the architect Julio Lafuente won a competition in 1957 to build a monument at Auschwitz. This eventually took ten years to complete, and underwent several changes before being completed to a design by Pietro alone and another architect, Giorgio Simoncini. Bleak and elemental, it takes the form of blocks and columns on the site of the death camp’s railway station.

Rodin, Brancusi and the surrealist artist Sebastian Matta were all influences on Cascella’s sculpture, but he drew most heavily on his memories of childhood in the Abruzzi mountains — the sun, the water, the turning of mill-stones. He worked with rough-hewn and primordial forms, somewhat Cubist in their geometry and assemblage, but less daring in their execution. Marble and stone — “the bones of the earth” — were his favoured media.

His commissions included the Arch of Peace (1971) for Tel Aviv, a memorial to Giuseppe Mazzini (1974) for Milan and a giant abstract ship (Nave, 1987) for his home town of Pescara. Among his other works were a sculpture for the centenary of the Barilla pasta company (1982) of Parma, and a monument to the Resistance (1979) for Massa-Carrara, in the marble-producing hills of northeastern Tuscany and near the 11th-century castle in Pietrasanta, which was Cascella’s home.

While creating pieces in 1984 for the Campo del Sole open air museum near Lake Trasimene, Cascella met his second wife, Cordelia von den Steinen, herself a sculptor. She survives him together with his two sons and two daughters.

Pietro Cascella, artist, was born on February 2, 1921. He died on May 18, 2008, aged 87