Arata Isozaki, a prolific Japanese architect, urban planner and theorist who received a belated Pritzker Architecture Prize at the age of 87, died Wednesday at home in Okinawa. He was 91.

His death was confirmed by his longtime companion, Misa Shin, in a statement.

Practicing at a time of seismic shifts in architectural practice and theory, Isozaki was both an agent and messenger of change who never repeated himself in his work. Each of his buildings was unique and escaped signature.