Foundation’s Fear by Gregory Benford, Foundation and Chaos by Greg Bear, and Foundation’s Triumph by David Brin make up The Second Foundation Trilogy. This is a continuation of Isaac Asimov’s Foundation trilogy.
The issue: A matter of context. The story is that two foundations were established at opposite ends of the galaxy: the First Foundation and the Second Foundation. This second trilogy is not about the Second Foundation, but one might think so if one had read the first trilogy.