One of the headline stories from the new Debrett's database concerns the 9th Earl of Mt. Edgcumbe.
The 8th Earl, Robert Charles Edgcumbe, died on June 12, 2021. The assumption was that he was succeeded by his next brother, Piers Valletort Edgcumbe (b. 1946). Richard even posted that succession back in early July.
According to the database, Piers actually predeceased his older brother. He died in 2019.
Succession thus passed to the youngest brother, Christopher George Mortimer Edgcumbe (b. 1950), who is the 9th Earl.
The new Earl has 2 sons. The elder son, Douglas George Valletort Edgcumbe (b. 1985) is currently known with the courtesy title of Viscount Mount Edgcumbe and Valletort.