Mogul is an eponym for an important and influential magnate.
The word comes to us from a Muslim dynasty that was established in India in 1526 and flourished until 1857; the empire was also known as Mughal or Mongol. It was founded by Babur, a Turkish leader who invaded and occupied Delhi and Agra. He was succeeded by his son Humayun, who wasn't as astute a leader as his father; he lost the empire to the Afghan chieftain Sher Khan. Then came Humayun's son Akbar, greatest of the Mughal emperors; he reestablished Mughal power and expanded his territory immensely. His son Jahangir and grandson Shah Jahan further consolidated the empire, and Shah Jahan was the one who had many impressive monuments and buildings, such as the Taj Mahal, constructed. After Shah Jahan the empire went into decline, suffering from Hindu revolts, dynastic struggles, and incursions from Persia and Afghanistan. The British took control of the empire in the late 18th century and maintained puppet Mogul emporers until the mid-19th century, after which it ceased to exist even in name.
Today only the gorgeous works of art and architecture, and the term mogul itself, remain to remind us of the glory of this once-great empire and the power of its rulers.