Freud, who turns 80 this year, is a realist painter in an age of gloss and abstraction, accused by critics of emphasizing human ugliness, putrefying flesh and death in his brutally frank portraits. Late last month the Tate Britain opened the largest retrospective of Freud’s work, displaying more than 180 paintings. Some, like a striking new self-portrait and a nude of his 27-year-old girlfriend, are so recent the paint is barely dry. Others, from private collections, have never before been exhibited and are unlikely to be seen in public again for decades. Works in progress, including the as-yet-unfinished portrait of a pregnant Kate Moss, may be added as they are completed. Two notable paintings are absent: his shockingly unflattering image of the queen remains at Buckingham Palace for the current Golden Jubilee celebrations, and a portrait of the artist Francis Bacon, who was part of the same Soho pub gatherings as Freud in the 1950s, was stolen from an exhibit in Berlin in 1988 and, despite the artist’s personal pleas, has never been returned.

Freud revels in teasing out the physical evidence of a life richly lived: laughter lines, lumps of fat, sagging flesh. And he has persisted in deepening his ability to depict them at a time when gyms and Botox clinics are overflowing with clients eager to smooth out these insidious betrayals of their humanity. His fascination with mortality comes partly from his famous grandfather Sigmund, who joined the family in London in 1939 after they had all fled Nazi Germany. Sigmund, whom Lucian adored, had studied the culture of ancient Egypt, its death-centered faith and in particular the pharaoh Akhenaten, who broke with the formulaic tradition of Egyptian art to commission lifelike images of himself. Large, bulbous eyes and wide faces gaze from Freud’s early portraits, echoing the death masks in his well-thumbed copy of a 1934 picture book, “Geschichte Aegyptens” (“History of the Egyptians”), to which he has turned for inspiration throughout his career.

Unlike Damien Hirst’s maggot-soaked hunks of meat, Freud’s work demonstrates that the ugly reality of decay can radiate a painfully complex beauty. After his father died in 1970, Freud cared for his profoundly depressed mother the only way he knew how: having run from her claustrophobic attentions during his adolescence, he asked her to sit for him, and she did. For hours daily he painted her, creating works that rival those of Whistler and Rembrandt. Sleepless, tear-filled nights and lost hope are visible in her slack, white flesh. He observed her grief intimately, creating a study of how an apprehensive person settles into the knowledge that this is the last decade of her life. When she, too, died, in 1989, sitting by her bed he drew her again.

It isn’t just the notion of imminent death that animates Freud. The exhibit gives the sense, strangely reassuring, that Freud has been present at every significant stage in his subjects’ lives. He records in minute detail the multiple layers of feeling with which his sitters are assailed as they recline–sometimes unguarded and passive in sleep. Close observation for months on end–Freud often takes more than 70 sittings of several hours each–leaves a touching, intimate chronicle of busy, chaotic lives and extended, broken families. He completed “Naked Portrait II” the day before the exhausted, swollen subject gave birth. The round folds of the white chemise in which the subject of “Baby on a Green Sofa” sleeps suggest her burgeoning personality. (She is one of Freud’s eight daughters, Bella, who is now a well-known fashion designer.) To force the viewer to focus on the paintings’ content rather than superfluous gossip about the subjects, the pictures in the exhibit, annoyingly, do not have labels next to them and their subjects are not named.

The exhibit’s curator, William Feaver, noted that the passionate dislike that Freud’s work has sometimes sparked often reflects the viewer’s own fears and preoccupations, rather than those of the artist. He gently mocked a critic who once suggested that Big Sue, a government worker of generous proportions whom Freud began painting in the mid-1990s, was probably the only one of Freud’s models the famously promiscuous artist hadn’t bedded–a Freudian slip revealing what was on his own mind. Whether we harbor a narrow, glossy-magazine notion of beauty or a secret revulsion at the signs of aging, Freud lets us see our own less attractive characteristics. Physical perfection doesn’t interest him, and he works from friends and characters who intrigue him, rather than solely from professional models who, accustomed to nakedness, develop a second, defensive skin that obscures the complex inner world Freud wants to draw out.

Referring to the pharaoh Akhenaten, Freud has described “the terrific loneliness of the king.” A notoriously reclusive artist, he knows that feeling all too well. Freud is one of a handful of artists working today who look to masters like Titian and Goya for inspiration, and whose work could stand alongside theirs. His grandfather devoted his life to proving that we are ruled by unconscious desires that are beyond our control, and Lucian Freud’s retrospective shows that exploring these forces need not create a chronicle of decay and degradation. By laying bare his subjects’ awkwardnesses and idiosyncrasies, he has discovered in each a breathtakingly strong and intimate sense of self: palpable, desperately flawed and all the more beautiful for not being Botoxed.