Vincent Phantomhive

Earl Vincent Phantomhive (ヴィンセント ファントムハイヴ Vinsento Fantomuhaivu) is the late head of the Phantomhive family, and is who Ciel Phantomhive inherited his titles from.

Vincent was the head of the Phantomhive household and acted as Queen Victoria's watchdog, both titles that Ciel later took over. Tanaka has shown to have worked for the Phantomhive family at least since Vincent's time.
Sometime while he was alive, he hosted a variety of parties that many others nobles attended. When Baron Kelvin attended one of these parties, it is the first time that he encountered Ciel, and he made a continued effort to network with Vincent after that. While Vincent was kind, the others were not, causing Baron Kelvin to believe he had to be more "beautiful" to be accepted by their social circle. As a result, Vincent is indirectly part of the reason for Baron Kelvin's obsession with undergoing plastic surgery and with Ciel.
On Ciel's tenth birthday, Vincent and his wife were killed in a fire, his son was kidnapped, and his manor was burnt to the ground. It seems that the reason for this was related to his work as the queen's watchdog and his control over the underworld. In the anime, his death is directly attributed to Queen Victoria.