(FORTUNE Magazine) – The Arab oil embargo of 1973 began what has been dubbed the greatest intercontinental transfer of wealth since Spain sacked the New World. While Western motorists seethed in gas lines, greenbacks set sail by the galleonful, coming to rest finally in the pockets of a few Mideast monarchs. Not only are these rulers different from you and me, they are different from the guilty, self-effacing, whale-watching rich of Europe or America. These are men with harems. With caravans. Men in whose domain zest and romance still walk hand in hand with wealth, unashamed. Fahd of Saudi Arabia is richest. No line separates his fortune from his nation's, and his visitation rights to the Saudi treasury are generous. The pool of foreign currency into which he can dip holds, at its deep end, $20 billion, of which more than $2 billion is in the pleasantly liquid form of gold. The largest share of all this, which still excludes the value of Saudi oil reserves, belongs to Fahd, so long as he remains king. One of 52 sons born to King Abdul Aziz, founder of the desert kingdom, Fahd quickly acquired a reputation as a rakehell. French newspapers carried front- page stories of his gambling losses on the Riviera, which once ran to $500,000 in a single night. Grown fat, he lolled on Spain's Marbella Coast, whose blue waters, cool breezes, and abbreviated swimsuits beguiled him and whose spas promised slenderness. By his mid-40s, however, in expectation of someday becoming king, he began a program of self-reform that he continues to this day. Last year he told Saudis to start addressing him as ''Custodian of the Two Holy Places,'' meaning Mecca and Medina, a gesture seen as Fahd's way of reminding Moslem fundamentalists that his impieties are a thing of the past. Home to Fahd can mean his residence off London's Hyde Park, his French Riviera Chateau de l'Horizon (former seat of Rita Hayworth and the Aly Khan), or his $24-million Little Versailles, whose 27 rooms, clad in beige Italian marble, overlook Lake Geneva. Right now, with the help of 40 cranes, he is building a new palace in Riyadh to replace his old digs in Jiddah. When construction of the Jiddah palace was already well along in 1983, Fahd noticed that guests atop a nearby Intercontinental Hotel could look down into his garden. Disconcerted, he bought the hotel and made it the palace guest house.

Whether by land, sea, or air, Fahd in transit is formidable. His new yacht, the 500-foot Abdul Aziz, is the largest in the world, with appointments that include a 100-seat theater, a mosque, bullet-proof portholes, antiaircraft guns, an intensive care unit, and accommodations for 60 understandably nervous guests. In the air Fahd has his choice of two 747s: a 747-SP and a newer 747-300 (''a big one,'' says Boeing). The latter, by one account, has a rotating throne whose clockwork keeps it pointed toward Mecca no matter in which direction the plane is heading. On land Fahd plies the sands in a Wanderlodge -- a four-wheel-drive motor home built atop a 40-foot bus chassis and fed from a 300-gallon gasoline tank. Fahd instructed the U.S. builders to replace the 60-square-foot bedroom (standard equipment) with a throne room. He may also have made changes to the lodge's horn, which ordinarily comes programmed to play up to 60 tunes, including Rocky, Amazing Grace, and America. When Fahd comes calling, other heads of state can feel a little short. After visiting President and Mrs. Reagan in 1985, he gave them a diamond-studded purse of woven gold, a gold pitcher encrusted with gems, and a bejeweled clock inside an enamel egg. The Reagans gave Fahd a copy of Birds of America -- a very nice copy, of course. The Saudi King's reverence for things Western is not shared by his fellow monarch, Zaid al Nahayan of Abu Dhabi, who alone among Gulf rulers can claim to be a true son of the desert. Not for him the gaming tables of Monte Carlo. He prefers the Sudan, where he races horses and hunts prey with falcons. Still graceful and hard-muscled at 71, with brooding eyes and a hawk's profile, he looks like central casting's ideal of the desert prince. Guests arriving at his castle -- a whitewashed fort with crenelated towers -- are apt to find him seated cross-legged on the floor, his forearm resting on a saddle. He often speaks in aphorisms (''Better to have the problem of spending than the problem of no money''), and he enjoys the gift of understatement (''Frequently small countries have advantages which others do not, such as oil''). Unlike his predecessor, a miser who kept the nation's wealth in gold bricks under his bed, Zaid spends freely. When his eldest son married in 1981, Zaid's feast cost $40 million and required construction of a 20,000-seat amphitheater. Usually a cautious investor, Zaid once played the commodity markets unwittingly when an adviser, against his orders, bought futures in copper and gold. The loss that resulted, $95 million, can hardly have put a dent in Zaid's $1.5-billion fortune, but the adviser was consigned to prison for disobedience and fraud. If Zaid's management is homespun and Fahd has the work habits of a college sophomore -- bouts of languor redeemed by furious activity -- their neighbor to the north, the six-foot Emir of Kuwait, is every inch a working ruler. Jaber al Sabah is so punctual that his neighbors at the British embassy used to say they could set their watches by his comings and goings. Unhappily for him, the British were not the only ones setting their watches. In 1985 a car bomb attack on his motorcade set aides to tweezing glass shards from the royal forehead. No longer does he shop in person for dinner at the local fish market, there to drink tea and visit with his subjects. Yet he has much to console him. With five brothers he controls some $5 billion, which flows from oil reserves that should last 245 years.

The Emir's vigor sets him apart not only from Fahd, who reportedly takes injections of live sheep cells as a restorative, but also from Sheikh Rashid al Maktoum, ruler of Dubai, whose debilitating 1980 stroke forced him to relinquish much authority to his four sons. Of these, 39-year-old Mohammed is the real power not just in Dubai, but also in Kentucky, where at Lexington's Keeneland Race Course last year he spent $25 million in two days to acquire 28 yearlings. He has paid up to $10.2 million for a single animal, prompting some to suggest that the statue of the racehorse Fair Play (sire of Man o' War) in the town square be replaced with one of Sheikh Mohammed. Experts put the family's resources at around $2 billion. Horses have likewise left a mark on Morocco's King Hassan II, who was kicked in the face by one as a boy. No great fan of racing, Hassan prefers golf, a passion he gratifies with the help of a $1.3-billion inheritance. As an adjunct to his eighth and most recent palace, he installed a 45-hole outdoor golf course. (Three palaces have indoor courses.) On the green, a chamberlain in white burnoose and peaked red fez holds his cigarette while he putts.