Declaration of the Covenant of the Deep
When the Covenant of the Deep felt that it was strong enough to bring their aim of uniting the disparate factions and peoples of the Underdark together in an egalitarian community, guided by their new deity, Drusiss, the Divine One, the Covenant’s leadership sent a letter to the heads of all factions, large towns and cities in the Underdark, urging them to join the Covenant in its crusade, or be destroyed.
The purpose of the declaration was simple, to easily allow the Covenant of the Deep to establish who stood for them, and who should be earmarked for elimination. By the time that the missive was sent, the Covenant already had a large base of support across all levels of the Underdark, so they were confident that they could crush any opposition that stood in their way. Their declaration represented their first open move on the political scene of the Underdark and brought them to the attention of all of those factions who hadn’t up until that point been aware of their existence or their machinations, or those who hadn't taken the seriously up to that point.
Prior to the distribution of the declaration, the Covenant of the Deep had spent years of careful espionage establishing themselves from their base of the Hellspire Citadel in the Deep Underdark, from which they had slowly but surely gathered support for their cause amongst the Drow poleis, Duergar city-states and all manner of other creatures and settlements. When it was felt amongst the leadership that they had gathered enough support and strength of numbers to not be crushed by a retaliatory party, they stepped out of the shadows and onto the stage of Underdark politics, using the declaration letter, which was sent to all large cities and settlements as a way of identifying potential allies and enemies.