Set 20 years after the events in the Merlin books and Short Stories, Ancient Powers takes place during a period of Civil War within the Courts of Chaos.
King Moloch now sits upon the throne of Chaos, how long he shall remain there is unknown. Shortly before Merlin was to be crowned King in Chaos, civil war broke out in the Courts with Merlin on one side, and Moloch and his (greater number) of supporters on the other. After 16 years of conflict, assassination, and in-house fighting Moloch and his forces managed to take Thelbane.
Moloch corwned himself King of Chaos shortly thereafter and has ruled in Chaos for the past 4 years. Chaos is now under a strict state of Martial Law, with Merlin and his supporters in exile.
All of which does not bode well for Amber. Many of those that supported Moloch did so because they refused to see an Amberite Half Breed on the Throne. Moloch used the old animosity of Chaos towards Amber to gain support during the War. Now that he sits upon the Throne, Random and the other Princes of Amber fear another War with Chaos.