Question: How many Royal families did Empress Matilda belong to?
Sentence (from "Geoffrey Plantagenet, Count of Anjou"): By his marriage to the Empress Matilda, daughter and heiress of Henry I of England, Geoffrey had a son, Henry Curtmantle, who succeeded to the English throne as King Henry II (1154-1189) and was the first of the Plantagenet dynasty to rule England; the name "Plantagenet" was taken from Geoffrey's epithet.
Relevant evidence: Yes