Some of the richest people must have been one of the more powerful pharaoh's and that Chinese ruler that constructed the terracotta warriors and resides in an un-excavated tomb that apparently contains jewels to represent the sky and rivers of mercury.
Okay so I did some research and I nominate
Qin Shi Huang, the first emperor of China, to be the most powerful (rated by his absolute power over his people), and richest of all time. He was the first emperor to start constructing the great wall of China, he created the terracotta warriors and here's a description of his tomb:
Quote:
Mausoleum of the First emperor
The Chinese historian Sima Qian, writing a century after the First emperor's death, wrote that it took 700,000 men to construct it. The British historian John Man points out that this figure is larger than any city of the world at that time and calculates that the foundations could have been built by 16,000 men in two years. While Sima Qian never mentioned the terracotta army, the statues were discovered by a group of farmers digging wells on March 29, 1974. The soldiers were created with a series of mix-and-match clay molds and then further individualized by the artists' hand. Han Purple was also used on some of the warriors.
Qin Shi Huang's tomb
One of the first projects the young king accomplished while he was alive was the construction of his own tomb. In 215 BC Qin Shi Huang ordered General Meng Tian with 300,000 men to begin construction. Other sources suggested he ordered 720,000 unpaid laborers to build his tomb to specification. Again, given John Man's observation regarding populations of the time (see paragraph above), these historical estimates are debatable. The main tomb (located at 34°22′52.75″N 109°15′13.06″E) containing the emperor has yet to be opened and there is evidence suggesting that it remains relatively intact. Sima Qian's description of the tomb includes replicas of palaces and scenic towers, 'rare utensils and wonderful objects', 100 rivers made with mercury, representations of 'the heavenly bodies', and crossbows rigged to shoot anyone who tried to break in. The tomb was built on Li Mountain which is only 30 kilometers away from Xi'an. Modern archaeologists have located the tomb, and have inserted probes deep into it. The probes revealed abnormally high quantities of mercury, some 100 times the naturally occurring rate, suggesting that some parts of the legend are credible. Secrets were maintained, as most of the workmen who built the tomb were killed.