VIENNA, JULY 11 -- Czechoslovakia's reformist president, Vaclav Havel, today named as his chief of staff the head of one of Europe's oldest aristocratic families, Prince Karl Johannes von Schwarzenberg, who had been barred from his ancestral country by its previous Communist rulers.

The chief task for Schwarzenberg, who has forsworn any effort to reclaim his family's vast nationalized land holdings or dozen palaces and castles, will be to bring efficiency and professionalism to a newly powerful administration that so far has been a make-shift affair staffed largely by intellectuals and theater workers.

While people with ties to former monarchies and aristocracies have been rigorously shunned by other evolving new governments in Eastern Europe, Schwarzenberg, 52, brings clear democratic credentials, including his past six years as president of the Vienna-based International Helsinki Federation for Human Rights, a job in which he emerged as a forthright advocate for political change in Eastern Europe.

"He is a political personality, a combination of patriot and cosmopolitan who is widely read in Czechoslovak affairs and is a typical European," Havel said in announcing Schwarzenberg's appointment at a Prague news conference.

As chief of staff of what has developed into a super-presidency from which major legislative and foreign policy initiatives will emanate, Schwarzenberg is expected to wield significant influence in the new government.

Schwarzenberg -- whose forebears include autocratic Prince Felix Ludwig Schwarzenberg, Emperor Franz Josef's prime minister who restored order to Austro-Hungary after revolutions in 1848 -- takes the long historical view of his surprising return.

"Thank God we have now achieved a situation where nobody is excluded for historical reasons," he said in a recent interview. "One should not see the history of a country in just one day or 20 years, it's a long flow. . . . Be it a worker, be it a peasant or be it somebody like me, we're all part of the history of a very old country."

Soon after longtime dissident Havel became head of state last December, Schwarzenberg, in his fire-red Porsche, began dashing back and forth weekly between his baroque palace in Vienna and the presidential offices in Prague's Hradcany Castle.

Initially Schwarzenberg was only a part-time adviser to the interim president, but Havel, who was elected to a two-year term last week, today named him as his full-time chief of staff. He will direct the newly reorganized presidential offices, overseeing eight departments, handling domestic and foreign policy, economics, culture, human rights, press, legal and social affairs.

The job is a remarkable homecoming for the Prague-born Schwarzenberg, who at age 11 retreated south to Austria after the 1948 Communist takeover of Czechoslovakia. His human rights activities, he said, have been motivated in part by the memory of an uncle sent to Buchenwald under the Nazis and another forced to work in a Czechoslovak uranium mine under Stalinism.

Schwarzenberg said he would not try to regain his family's confiscated properties and doubted that any would be returned. "We are not the only ones who lost everything," he said. "It's up to the people and their representatives what kind of an economic and social system they will have and what importance former private property will have. . . . I can't claim a special position and I would never do that."

"Forester and innkeeper" is how Schwarzenberg, black moustache carefully cropped and puffing on a pipe, refers to himself. This modest description is balanced, however, by his listing in the Vienna telephone directory as "Erbprinz" -- or "Hereditary Prince" -- von Schwarzenberg, although the use of such titles is illegal in the Republic of Austria.

Trained in law and forestry management at universities in Vienna and Graz, Schwarzenberg also has 25 years' experience heading personal business interests, including 60,000 acres of woodland in southern Austria -- one-fifth his family's lost holdings in Czechoslovakia. He has transformed his family's splendid 17th century Vienna palace into a choice hotel where he, his wife and three children live in a wing overlooking several acres of walled gardens.

Since the toppling of Communist rule in December, several of playwright Havel's colleagues have complained of dilettantism at the top of the new government.

"A state of chaos would be the wrong expression," Schwarzenberg recently said of the situation in Havel's office. "If you come to a place where a new house is being built, it may create a rather chaotic impression without necessarily being chaotic. We are starting from scratch, because you must not forget that the president's office in Czechoslovakia during the past 40 years was an ornament for the boss of the Communist Party, nothing else. The real political decisions, power and everything resided in the Central Committee of the party and its general secretary.

"I hope slowly to professionalize the office, to bring in on the lower echelon some new, efficient people, to broaden the structure a bit."

"He is the only one of us who has ever run an office of any size," Havel's press secretary, Michael Zantovsky, said of Schwarzenberg.

As head recently of a committee of prominent exiled Czechs and Slovaks, including film director Milos Forman, who have offered aid to their homeland, Schwarzenberg enlisted Forman's costume designer, Theodor Pistek, to make resplendent new uniforms in national colors of blue, red and white for castle guards who formerly paraded in Soviet-style olive drab.

"These bright uniforms are important because they are a visible sign that the drab time is over" in Hradcany castle, Schwarzenberg said. "But of course this is also now a policy center where one really works, and works like hell. That's a basic difference."