where q is any prime number congruent to 7 modulo 8, with ring of integers O and Hilbert class field H. Suppose p [H : K] is a prime number which splits in K, say pO = pp * . Let H∞ = HK∞, where K∞ is the unique Zp-extension of K unramified outside p. Write M (H∞) for the maximal abelian p-extension of H∞ unramified outside the primes above p, and set X(H∞) = Gal(M (H∞)/H∞). In this paper, we establish the main conjecture of Iwasawa theory for the Iwasawa module X(H∞). As a consequence, we have that if X(H∞) = 0, the relevant L-values are p-adic units. In addition, the main conjecture for X(H∞) has implications towards (a) the BSD Conjecture for a class of CM elliptic curves; (b) weak p-adic Leopoldt conjecture.