Sirius Black II

Sirius Black (1877 - 1952) was the eldest son of Phineas Nigellus and Ursula Black. He married Hesper Gamp, and had three children: Arcturus, Lycoris, and Regulus Black, and is thus the great-grandfather and namesake of Sirius Black III.

Behind the scenes

 * Based on a statement by Horace Slughorn, Sirius may have been a member of the Slytherin House. That would make him the only Sirius Black who was sorted into Slytherin house; Sirius Black I died before going at Hogwarts and Sirius Black III was sorted into Gryffindor house. However, he attended Hogwarts c. 1888 - 1895, when Slughorn wasn´t Potions teacher.
 * Sirius II was named after his paternal uncle who died very young.
 * Sirius II named his son Arcturus after his brother, or after his great uncle.

Etymology
Sirius is the name of the Dog Star, which is very bright.

Notes and references
Sirius Black II