[3] After studying in Paris, he went to Rome,[4] where he moved in the same circles as the painters Alexander Runciman and James Barry.

Besides subjects from classical mythology such as the Diomedes Stealing the Palladium, which he sold to the British collector, Thomas Mansel Talbot, in 1772, he also sculpted a colossal representation of The Muse of History Recording the Deeds of Gustavus Adolphus, in which are depicted the achievements of King Gustav II Adolf before the Chancellor, Axel Oxenstierna.

It was in Rome also that he modelled the statue of King Gustav III, subsequently cast in bronze and purchased by the city of Stockholm in 1796.

While primarily a sculptor, Sergel (inspired by English artists like Thomas Rowlandson) also drew sequential picture stories, an early form of comic strip.

He was an important part of the artistic elite in Stockholm, drawing a portrait of Sweden's bard Carl Michael Bellman among others.