Question:  Anthony Charles FitzClarence was the last of the senior male line that began with the third son of George III and younger brother and successor to who?
Sentence (from "Anthony FitzClarence, 7th Earl of Munster"): The Earl of Munster was the last of the senior male line of FitzClarences that began with King William IV (Duke of Clarence until his accession in 1830) and his mistress, the comic actress Dorothea Jordan (née Bland).
Relevant evidence: Yes