Generate a Complete D&D Campaign Setting with Political Intrigue

Create a comprehensive Dungeons & Dragons campaign setting for [a maritime empire in decline]. Include [detailed descriptions of 5-7 major city-states with unique cultures and governments], [a pantheon of 8-10 deities with their domains and conflicts], [three major political factions vying for power], and [an overarching mystery involving ancient sea creatures]. Develop [10 notable NPCs with complete stat blocks, motivations, and secrets], [regional maps with trade routes and points of interest], [a timeline of historical events spanning 500 years], and [hooks for 15-20 side quests]. The setting should feature [themes of colonialism, resource scarcity, and magical pollution]. Include [unique magic items tied to the setting's lore], [regional variants of common monsters], [festival calendars and cultural traditions], [economic systems including currency and trade goods], and [consequences for player choices that affect the world state]. Provide [session zero guidance], [safety tools recommendations], and [scaling suggestions for levels 1-15].