Never before, or since, has such a large empire been ruled by women.

As the war campaigns extended farther away and grew ever longer during the 13th century, women expanded their control and assumed public office as rulers.

This is especially true for most of the years between the reign of Genghis Khan, which ended in 1227, and that of his grandson Khubilai, which commenced in 1260.

Genghis Khan's son Ogodei became Great Khan in 1229. However, he increasingly spent his time in drunken binges. As a result, power gradually conveyed to Toregene, the most capable, although not the senior, wife.

The oldest surviving evidence of Toregene's authority in the Mongol court appears in an order to print Taoist texts issued by her as Yeke Khatun, Great Empress, under her own name, but still under the seal of Ogodei on April 10, 1240. The document shows clearly that she already controlled part of the civilian administration of the empire.

While the men fought, she pursued an entirely different line of activities supporting religion, education and construction projects on an imperial scale.

Soon thereafter Ogodei died, probably in an alcoholic stupor — and in 1241, Toregene assumed complete power as regent.

The Mongol women were a strange sight to the civilizations that they helped conquer. They rode horses, shot arrows and commanded both men and women.

In pursuit of her own policies, she dismissed her late husband's ministers and replaced them with her own, the most important of whom was another woman, Fatima, a Tajik or Persian captive from the Middle Eastern campaign.

The Persian chronicler Juvaini, who seemingly disapproved of women's involvement in politics, wrote that Fatima enjoyed constant access to Toregene's tent. According to him, she "became the sharer of intimate confidences and the depository of hidden secrets."

Fatima played a political role while the older "ministers were debarred from executing business, and she was free to issue commands and prohibitions."

During Toregene's reign, foreign dignitaries arrived from the distant corners of the empire to her capital at Karakorum or to her nomadic imperial camp. Emirs, governors and grandees jostled along the same roads as princes and kings.

The Seljuk sultan came from Turkey — as did representatives of the Caliph of Baghdad. So did two claimants to the throne of Georgia: David, the legitimate son of the late king — and David, the illegitimate son of the same king.

The highest-ranking European delegate was Alexander Nevsky's father, Grand Prince Yaroslav II Vsevdodovich of Vladimir and Suzdal, who died suspiciously just after dining with Toregene Khatun.

In addition to the rule of Toregene and Fatima from Karakorum in Mongolia, two of the other three divisions of the empire also had female governors.

A chronicler wrote that if history produced only one more woman equal to Sorhokhtani, then women would have to be judged as the superior sex.

Sorkhokhtani, the widow of Genghis Khan's youngest son Tolui, ruled northern China and eastern Mongolia. Ebuskun, the widow of Genghis Khan's second son Chaghatai, ruled Central Asia or Turkestan.

Only the Golden Horde of Russia, under the control of Batu Khan, remained under male rule.

Not only were most of the rulers women, but surprisingly, none had been born Mongol. They had married into the family from a conquered steppe tribe, and aside from Fatima, most of the women were Christians. In the Mongol world, neither gender nor religion hindered these women's rise to power.

Never before, or since, has such a large empire been ruled by women.

Toregene passed power onto to her inept son Guyuk in 1246, but within 18 months, he lay dead under still unexplained circumstances. In the continuing political struggles at the center of the empire, the fringes began to unravel.

With his great love of metaphors, the chronicler Juvaini wrote: "The affairs of the world had been diverted from the path of rectitude and the reins of commerce and fair dealing turned aside from the highway of righteousness." He described the land as being in darkness, "and the cup of the world was filled to the brim with the drink of iniquity."

The Mongol people and their subjects, "dragged now this way, now that, were at their wits' end, for they had neither the endurance to stay nor did they know of a place to which they might flee."

After Guyuk's brief reign, it was time again for a woman — his widow Oghul Ghamish — to step forward and take control of the empire — just as her mother-in-law Toregene had done a decade earlier.

In China, the Mongol women rejected foot binding — and in the Muslim world, they refused to wear the veil.

However, the other powerful woman of the empire — Sorkhokhtani — quickly contested her rule. With the full support of her four capable sons and a lifetime of preparation and waiting, Sorkhokhtani organized the campaign of election of her son to the office of Great Khan.

On July 1, 1251, the assembled Mongol throng proclaimed the election of her son, the 43-year-old Mongke.

Whereas Genghis Khan himself had produced sons who were relatively weak, prone to drink and self-centered, Sorkhokhtani had produced and trained four sons destined to make a major mark on history.

Each of her sons was a khan. In the coming years, Mongke, Arik Boke and Khubilai would all carry the title of Great Khan, for various lengths of time, and her other son, Hulegu, became the conqueror of Baghdad and founded a new dynasty of the Persian Ilkhante.

So great was her achievement that a Persian chronicler wrote that if history produced only one more woman equal to Sorhokhtani, then surely women would have to be judged as the superior sex.

The Mongol women presented a strange sight to the civilizations that they helped conquer. They rode horses, shot arrows from their bows and commanded both men and women.

Not only were most of the rulers women, but surprisingly, none had been born Mongol.

In China, the Mongol women rejected foot binding — and just as in the Muslim world, they refused to wear the veil.

Yet, quickly after settling down in their newly conquered lands, Mongol women lost public power. Only in Mongolia did they continue to rule and to fight.

While Khubilai Khan ruled from the Chinese capital he founded at Beijing, his cousin Khaidu continued to fight against him from Central Asia and, true to the Mongol traditions, Khaidu's daughter fought with him.

According to Marco Polo, who referred to her as Aiyaruk, she was both beautiful and powerful — and skilled as an archer and wrestler. She supposedly never married, because she vowed only to marry the man who could defeat her at wrestling, and none did. Her story, in part, inspired the 20th century opera Turandot by Puccini.

The empire of Genghis Khan ultimately lasted for a century and a half. By 1368, the Mongols were overthrown — and most of them withdrew to their steppe homeland.

By 1368, the Mongols were overthrown — but the women kept the imperial spirit alive.

While the men returned to squabbling over sheep and stealing horses, the women kept the imperial spirit alive. In the late 15th century, a new conqueror arose determined to restore the Mongol Empire of Genghis Khan.

She was Manduhai, known forever to the grateful Mongols as Manduhai the Wise Queen. She took to the battlefield and, one by one, re-conquered the steppe tribes and united them into a single nation.

But this time, they were no match for the Chinese who rapidly expanded the Great Wall to keep her out and who now used the new artillery of gunpowder to defeat her troops. The era of the great warrior queens of Mongolia had passed.