members, relatives and any friends who were capable of arming themselves. Darius believed that Intaphernes was planning a rebellion, but when he was brought to the court, there was no proof of any such plan. Nonetheless, Darius killed Intaphernes's entire family, excluding his wife's brother and son. She was asked to choose between her brother and son. She chose her brother to live. Her reasoning for doing so was that she could have another husband and another son, but she would always have but one brother. Darius was impressed by her response and spared both her brother's and her son's life. Military campaigns Egyptian campaign After securing his authority over the entire empire, Darius embarked on a campaign to Egypt where he defeated the armies of the Pharaoh and secured the lands that Cambyses had conquered while incorporating a large portion of Egypt into the Achaemenid Empire. Through another series of campaigns, Darius I would eventually reign over the territorial apex of the empire, when it stretched from parts of the Balkans (Thrace-Macedonia, Bulgaria-Paeonia) in the west, to the Indus Valley in the east. Invasion of the Indus Valley In 516 BCE, Darius embarked on a campaign to Central Asia, Aria and Bactria and then marched into Afghanistan to Taxila in modern-day Pakistan. Darius spent the winter of 516–515 BCE in Gandhara, preparing to conquer the Indus Valley. Darius conquered the lands surrounding the Indus River in 515 BCE. Darius I controlled the Indus Valley from Gandhara to modern Karachi and appointed the Greek Scylax of Caryanda to explore the Indian Ocean from the mouth of the Indus to Suez. Darius then marched through the Bolan Pass and returned through Arachosia and Drangiana back to Persia. Babylonian revolt After Bardiya was murdered, widespread revolts occurred throughout the empire, especially on the eastern side. Darius asserted his position as king by force, taking his armies throughout the empire, suppressing each revolt individually. The most notable of all these revolts was the Babylonian revolt which was led by Nebuchadnezzar III. This revolt occurred when Otanes withdrew much of the army from Babylon to aid Darius in suppressing other revolts. Darius felt that the Babylonian people had taken advantage of him and deceived him, which resulted in Darius gathering a large army and marching to Babylon. At Babylon, Darius was met with closed gates and a series of defences to keep him and