(FORTUNE Magazine) – FIAT GROUP, Italy's foremost industrial company and one of Europe's leading carmakers, is firing on all cylinders again. But don't give Giovanni Agnelli, Fiat's famous chairman and principal owner, the credit. The real turnaround artist is low-profile Chief Executive Cesare Romiti, 62. Says Chris Honnor, an analyst with the London stockbrokerage Kleinwort Grieveson: ''Agnelli is a wonderful ambassador and constitutional monarch. But Romiti is the man who has made everything happen.'' Ten years ago Fiat was sputtering so badly that it could raise desperately needed cash only by selling a $400-million stake to the Libyan government. Since Romiti took the wheel in 1980, profits have soared from $60 million to more than $1.3 billion. Fiat's comeback culminated this past fall. In the space of four weeks it paid $3 billion to buy out Colonel Qaddafi's bankers and bested Ford Motor Co. in a bid for Italy's ailing prestige carmaker, Alfa Romeo, by pledging to invest up to $5.5 billion over the next ten years. With his stiff jaw and ramrod posture, Cesare could easily pass for one of an earlier Caesar's centurions. Born and educated in Rome, he speaks with little of the southern Italian's exuberance. And he prefers not to talk about himself. ''My main contribution at Fiat has been to assemble a management team with a winning mentality,'' he says. His colleagues put things a little differently. ''Yes, there is a team here,'' says one executive, ''but Romiti is our coach.'' In a tribute to his tenacity, Italy's nickname-happy press dubbed Romiti Il Duro (the hard one). He typically spends 12 hours a day behind the massive desk in his plant-filled, paper-free office. He and his wife, Gina, live in the heart of Turin just minutes from Fiat headquarters; his two sons are investment bankers in Milan. Romiti says he has no amusements other than occasionally watching a Sunday game of Turin's famed soccer squad, Juventus. As a schoolboy, a visitor asks, did he ever imagine running a corporate giant like Fiat? ''Never,'' he replies. ''That would have been wishful thinking.'' Romiti moved to Turin as Fiat's chief financial officer in 1974, after a career in Rome that included stints as head of Italy's state-owned airline and telephone companies. For five years he labored in relative obscurity, decentralizing Fiat's top-heavy management structure, shedding marginal businesses, and imposing new financial controls. ''Back then people felt that getting out of any market meant an intolerable loss of face,'' he recalls. ''I tried to instill a new philosophy: Prestige comes from being in a market and making a profit, not remaining there at all costs.'' As Romiti describes it, one of Fiat's biggest problems was that ''our factories were ungovernable.'' Domineering unions insisted on intolerable overmanning of assembly lines and winked at widespread absenteeism. In September 1980, shortly after Agnelli chose him for the top spot, Romiti took a stand. At a time when layoffs were considered unthinkable in Italy, he announced that 23,000 Fiat workers must go. Despite a paralyzing general strike, Romiti, having crossed his Rubicon, never looked back. Five weeks later 40,000 Fiat workers marched through the streets of Turin expressing support for Fiat's management and demanding the right to go back to work. The union leaders swiftly capitulated. Says Romiti: ''On that day the turnaround at Fiat took place.'' Today Fiat produces the same number of cars it did in 1980, with 30% fewer workers. Its productivity and European market share match those of its principal competitor, West Germany's Volkswagen. Meanwhile Fiat's nontransportation businesses -- including telecommunications, robotics, bioengineering, aerospace, and financial services -- are mostly profitable and growing rapidly. Having shed the Libyans, Fiat was recently named prime contractor by the U.S. government for a $2-billion Star Wars project. Though Alfa Romeo hasn't made a profit in 13 years, Romiti says his team can drive it into the black within four years. Asked to compare the challenge at Alfa to the Fiat turnaround, Romiti dismissively waves his hand. He then smiles and offers this prophecy: ''In three years Fiat Group's revenues will double.'' Spurring a $17-billion-a-year industrial conglomerate to such hothouse growth would be the biggest triumph yet for Fiat's Roman capo. But coming from Romiti, the statement sounds less like a forecast than a command.