This originates from Pacific.
It was never part of any events. But when the Seers left UO, many of them instead of turning in their items they gave them to their friends. This particular Seer left soon after Trammel came out. She also had Talons Necklace, your boots, 1-2 other peices, but the most desirable one is the Terathian SilkSkin Shirt (which added 20 resistances) after AoS came out along with Vine cord sandles (the latter originated from Sonoma). Other items that people are familiar with from Seers are Sebratis book of memories, pure black deer mask, mellow yellow staff, and few others.