Deletion of Ernst-Johann Biron, Prince of Courland

Comment: Normally I would consider heirs to the Heads of former royal seats as notable but in this case the Duchy of Courland was annexed into the Russian Empire in 1795, 120 years before WWI, which lead to the fall of monarchy across Europe . The article thus completely fails to establish  in present times
Stance: delete
Cited policy: Wikipedia:Notability (WP:GNG)