Complex sentence: It is probable, but not certain, that Wulfric's family was linked with the Wulfric the Black to whom King Edmund granted land in Staffordshire and also to the Wulgeat who is a witness to charters in the reign of King Edgar.
Split into simpler sentences: It is probable that Wulfric's family was linked with the Wulfric the Black to whom King Edmund granted land in Staffordshire. The family was probably also related to the Wulgeat who is a witness to charters in the reign of King Edgar.