Phineas Nigellus Black (1847-1925) was a Headmaster at Hogwarts and early member of the Black Family. He was the father of Sirius, Phineas Jr., Arcturus, Belvina and Cygnus through his marriage to Ursula Flint.
Phineas's elder brother Sirius Black I died when Phineas was nearly seven years old by the fault of some muggle boys, resulting in his life-long hatred of muggles and muggle-borns.
He attended Hogwarts in Slytherin House from 1859 to 1866. He studied Ancient Runes and became a professor in 1880 at Hogwarts School of Witchcraft and Wizardry. He had previously married the school's nurse that resulted into five children:
- Sirius Black II (1877). Named after his brother.
- Phineas Black II (1880). Named after himself.
- Arcturus Black II (1884). Named after his uncle.
- Belvina Black (1886).
- Cygnus Black II (1889). Named after his father.
Phineas was a man with grey hair, previously black and dark eyes. He had a pointy beard.
Phineas was a sufficient, yet inpopular headmaster and also a strict father. He had a big hatred of muggles and muggleborn's. He cared about his relatives and blood purity an awful lot.
- His second name redirects to his great-grandfather Nigellus Black (1780).