London ? Leonardo da Vinci strove for perfection in his art — perfect beauty and perfect ugliness.

An exhibition drawn from the Royal Collection explores the Italian master’s lifelong quest to capture the human form — warts, wrinkles, blemishes and all — at its most exact and expressive.

“Leonardo da Vinci: the Divine and the Grotesque” includes several of the artist’s obsessively detailed anatomical studies as well as preparatory sketches for his masterwork, “The Last Supper.”

The walls also are lined with exaggerated sketches of gnarled old men, wizened old women and fierce, furry imaginary creatures.

“There’s a tension in Leonardo’s life between the divine and the grotesque — the twin poles of beauty,” said Martin Clayton, curator of the exhibition at the Queen’s Gallery at Buckingham Palace.

“One of the fascinations is seeing someone with such amazing skills as a draftsman creating something that is deliberately ugly.”

The 77 drawings, taken from Britain’s Royal Collection, were acquired by the royal family in the 17th century and normally reside at Windsor Castle, housed out of sight to limit the risk of light damage.

The chalk and pen-and-ink drawings include the artist’s early search for a scientific rule of “divine proportion” governing human beauty.

It was a common idea at the time, but Leonardo soon abandoned the quest — later works portray bodies as he found them, with anatomical accuracy.

“He absorbed current theories … but quickly realized that there was no basis for it and moved on to studying the human form dispassionately,” said Clayton. “No one pursued that as assiduously as Leonardo.”

The drawings span Leonardo’s career, from Florence in the 1470s through his final years in France, where he died in 1519. They illustrate his relentless quest to capture human character on paper and canvas.

“The good painter has two principal things to paint, that is, the man and the intention of his mind,” Leonardo wrote. “The first is easy, the second difficult.”

A masterful draftsman and a compulsive sketcher, Leonardo was also an inventor, philosopher and one of the great artist-scientists. The exhibition includes his remarkably detailed drawings of a sectioned skull, skeletons and the workings of the human mouth, as he strove to record the body with scientific precision.

Above all, there are heads — of angelic, curly haired boys, mature warriors and decrepit old men, types Leonardo drew compulsively all his life.

“He was fascinated and repelled by certain types of heads and kept on drawing them throughout his career,” Clayton said. “He couldn’t help himself.”

Again and again, Leonardo also distorted proportions to create comically grotesque figures that fascinated later artists.

The grotesque was a preoccupation of Renaissance art and architecture — gargoyles abound — but in Leonardo’s case seem to stem from, and mirror, his exploration of human beauty. The “twin ideas of divine and grotesque” run through his work, Clayton said.

While many now associated Leonardo primarily with the “Mona Lisa,” his “hugely influential” grotesques remained his best-known work for 400 years after his death in 1519.

One drawing in the show, of a farcically coifed overly made-up old woman, inspired John Tenniel’s Ugly Duchess in his illustrations for “Alice in Wonderland” in 1865.