Lord of Blackcrown is a title held by the head of House Bulwer, the ruler of Blackcrown in the Reach.
Lord Jon Bulwer died of a summer fever.
Lady Alysanne Bulwer is a lady-in-waiting of Margaery Tyrell in King's Landing.
Lady Alysanne and Queen Margaery play come-into-my-castle together. It is one of the things Ser Osney Kettleblack claims is preventing him from seducing Margaery.