How did Darius I administer such a large empire?

Darius I administered his huge, multicultural empire through good governance, the selection of loyal satraps, the use of taxation to pay for bureaucracy and the military, the standardisation of laws and weights and the use of the army to maintain control and order. This source-based homework task is designed for students of the NSW Ancient History Syllabus for the Australian Curriculum
Higher School Certificate course
Historical Periods
Option D: Persia from Cyrus II to Darius III
It can also be used as part of
Historical Societies
Option D: Persia in the time of Darius I and Xerxes