He's best known for his richly textured portraits of family and friends, and his paintings of the streets of Camden Town where he has lived and worked for 70 years.

But a hauntingly beautiful side of artist Frank Auerbach emerges from a show of portrait heads in charcoal, produced during his early years in post-war London.

A total of 17 large-scale drawings, made in the 1950s and 60s, are exhibited at The Courtauld Gallery in Somerset House, alongside a selection of six paintings that Auerbach made of the same sitters.Ham & High: The charcoal portraits hang alongside paintings of the same sitter such as Gerda Boehm from 1964The charcoal portraits hang alongside paintings of the same sitter such as Gerda Boehm from 1964 (Image: The Sainsbury Centre UEA courtesy Frankie Rossi Art Projects)

Curators say they push the medium beyond conventional limits, and show the importance of drawing to Auerbach's development as he found his voice as a young artist.

Many of the works were made in Auerbach’s studio in Mornington Crescent, which he took on in 1954 and where the 92-year-old artist still works to this day.

The series of charcoal heads sprang from numerous sessions with a handful of sitters who were important in his life, and who modelled for him over long periods. He spent months on each drawing working, erasing, and reworking them completely, sometimes breaking through the paper before patching it up and carrying on.

Ham & High: Frank Auerbach moved into his studio in Mornington Crescent in 1954 and has lived and worked in Camden Town ever sinceFrank Auerbach moved into his studio in Mornington Crescent in 1954 and has lived and worked in Camden Town ever since (Image: Geordie Greig)

This embattled process of creation mirrors Auerbach's painting technique, repeatedly layering on paint to create an image, then scraping it off at the end of the day until it is 'right'.

He considered the drawings to be of equal status to his paintings, and the charcoal allowed him to make works that are by turns unsettling and beautiful, and try to comprehend the unique presence of another person.

As Auerbach later put it: "I feel there is no grander entity than the individual human being… I would like my work to stand for individual experience.”

In expressing the fragility of life, they also connect to a city slowly rebuilding after the destruction and upheaval of the Second World War, which saw Auerbach's German-Jewish parents send him from Berlin to school in England at the age of seven for safety.

Ham & High: A self portrait from 1958A self portrait from 1958 (Image: Private Collection, courtesy Frankie Rossi Art Projects)

Both his parents were murdered at Auschwitz in 1942, and upon finishing school and arriving in London in 1947, Auerbach enrolled at St Martin's School of Art and later The Royal College of Art.

But it was additional life drawing classes led by pioneering artist David Bomberg at the Borough Polytechnic Institute - and his friendship with fellow art student Leon Kossoff - that inspired him to make the large charcoal heads as works that had equivalent status to his paintings.

The first in 1956 was of Stella West, with whom he had a long and intense relationship. West sat for him in her bedroom with Auerbach kneeling on the floor, his drawing board propped on an old chair, working long into the night.

He also made a group of portrait heads of Kossoff, two self-portraits, and a group of drawings of people he knew well, including his older cousin Gerda Boehm, and Julia Wolstenholme, whom he married in 1958.

Auerbach considered these works, produced over many months and always reworked from top to bottom at each session with the sitter until he deemed them finished, entwined with his painted portraits.

He worked on them alternately with the same intensity over extended periods. Such was their importance to him that his second solo-show at the Beaux Arts gallery in London in 1957 was dedicated to a group of the charcoal heads.

The exhibition at The Courtauld is the first time such a substantial group have been brought together from public and private collections. His remarkable post-war charcoal heads established Auerbach’s way of working and his fascination with the human form that has endured for more than seventy years.

Frank Auerbach The Charcoal Heads runs at The Courtauld until May 27.