Adam Clarke on Revelation 6:15

The kings of the earth, etc. - All the secular powers who had endeavored to support the pagan worship by authority, influence, riches, political wisdom, and military skill; with every bondman - all slaves, who were in life and limb addicted to their masters or owners.

And every freeman - Those who had been manumitted, commonly called freedmen, and who were attached, through gratitude, to the families of their liberators. All hid themselves - were astonished at the total overthrow of the heathen empire, and the revolution which had then taken place.