Ignatius Prewett

Ignatius Prewett appears on the Black family tapestry at 12 Grimmauld Place. He married Lucretia Black, sister of Sirius Black's father, Orion Black. It is suspected that he is related to Gideon and Fabian Prewett and their sister Molly (Prewitt) Weasley. Molly's son Percy has "Ignatuis" as his middle name, giving more support to the theory they are related.