THESE ARE hard days for royalists. One goes to bed at night secure in the knowledge that somewhere, at least, the elegance of monarchy reigns, only to waken at dawn to the sound of more tumbling tiaras.

Take the shah of Iran, for example. Last week somebody did. Right off the Peacock Throne, where he'd reigned as Shahanshah, Light of Iran, King of Kings, Shadow of the Almighty and Center of the Universe, complete with a palace, jewels and his own royal taster.

Once again it's a bear market in the king business, which hasn't really been healthy since Louis Quatorze.

The state of sovereigns, in fact, languishes in such pallid shape that the world numbers only 13 kings and three queens among its 160 or so heads of state.

That, at least, was the last official count from the Central Intelligence Agency, which keeps a tally on chiefs of state and cabinet members of foreign governments. Impermanance so roils our global stage that a new list comes out every month.

Things improve somewhat if one adds in the two emperors, two princes, one grand duke, three amirs, one sultan, one life president and a paramount ruler who head states and function in a kingly way.

But even there the standards are slipping. Emperor Hirohito of Japan, for example, has no real empire, and His Imperial Majesty Bokassa I of the Central African Empire -- an obscure army chief of staff not long before his $30 million coronation in 1976 -- is definitely nouveau rex.

Time in the saddle, after all, is the ultimate test of royalty, and has been since the strongest Piltdown man first clubbed others into submission.

Length of reign is the sole criterion used by the State Department in ranking monarchs for protocol, or was, at least, at President Kennedy's 1963 funeral, when Washington was last subject to a crowd of kings.

The royal pain these days, of course, is not only new kings but new countries. If the name of King Taufa'ahu Tupou IV doesn't spring readily to the lips of every king-watcher, perhaps it's because we can't place his Kingdom of Tonga. Who outside the World Bank knows where to find King Moshoeshoe II of Lesotho? Or King Jigme Singye Wangchuk of Bhutan?

The king business is obviously not what it was. In the past two decades, monarchs were deposed in Laos, Ethiopia, Afghanistan, Libya, Yemen, Zanzibar and Iraq, and the kings of Jordan and Morocco have lived through a series of assassination attempts.

The royal road, however, is not entirely a one-way street. Just when everyone had counted him out, Juan Carlos I returned as king of Spain to lead his country toward democracy, which not all kings care to do.

The fewer monarchs there are in the world, interestingly enough, the greater seems to be our fascination with royalty. Americans in particular, having had no royalty of their own, continue to yearn for it subconsciously, buying Buick Regals, Imperial margerine, queen-sized beds and the king of beers and watching "Fall of Eagles" on TV.

We like monarchs majestic and aloof and feel cheated when King Phumiphon Adunyadet of Thailand plays jazz saxophone with the royal orchestra or when the shah flies himself to exile (or maybe it was a vacation) at the controls of his own Boeing 707.

Those who take their royalty seriously will be comforted to know that the U.S. government does the same. It's important to know, for example -- and the State Department does -- that Amir 'Isa ibn Salman Al Khalifa of Bahrain is known as "Your Highness" while Prince Rainier of Monaco is called "Your Serene Highness."

Prince Rainier, by the way, is not among the CIA's listed heads of state, which may or may not account for his serenity.

The most complicated royal state in the world may lie in Malaysia, where the head of state is known as the Yang di-Pertuan Agong or Paramount Ruler.

The Yang is actually a sultan, one of the nine who rule Malaysia's nine member states and who every five years elect one of their number to preside over the country at large.

He is sultan for life, of course, but serves as Yang for only five years at a time, preceded by a five-year term as Timbalan Yang di-Pertuan Agong or Deputy Paramount Ruler.

While deputy he is known as "Your Royal Highness" just like any ruling grand duke. But when he gets to be Yang, he is known as "Your Majesty" in keeping with his role as sort of an emperor pro tem.

Once upon a time, we like to think, the king business was simpler than that: a treasure house of grace and elegance and all the other illusions we hoard in the deceptive woods of memory. But it never was simple as the tangled threads of history remind us.

If today there's poignance or absurdity in the Protector of the Peacock Throne awaiting runway clearance from the control tower, we might remember that kings and reigns generally pass away less violently in our technocratic age. No modern assassin has yet equaled the regicidal panache of medieval England when Edward II was put to death by reaming with a red-hot poker. Today, power passes with riots instead of wars, with night flights instead of knives and the major death is the death of illusion.