  We prove the Fargues-Rapoport conjecture for p-adic period domains: for a
reductive group G over a p-adic field and a minuscule cocharacter {\mu} of G,
the weakly admissible locus coincides with the admissible one if and only if
the Kottwitz set B(G,{\mu}) is fully Hodge-Newton decomposable.
