Sirius Black I (1845 - 1853) was a pure-blood wizard, possibly the eldest son of Cygnus Black and Ella Max, and the elder brother of Phineas Nigellus, Elladora and Isla. Sirius died when he was only eight years old, for unknown reasons.
Sirius is a name of the brightest star in the night sky. In the Black family there were also Sirius Black II (a nephew of Sirius I, son of Phineas Nigellus) and Sirius III, Walburga's and Orion's son. If Cygnus was his father, Arcturus Black I was his uncle.
Behind the scenes
- The reason why Sirius died so young, aged 7 or 8, is currently unknown. However, it is interesting to note that he died during the third cholera pandemic (1852–60) that claimed 23,000 lives in Great Britain, 10,000 lives in London alone. Even though J. K. Rowling has said that "a wizard could catch anything a Muggle might catch, but he could cure all of it", it could be the case that Sirius had not yet manifested his magical powers at the time due to his young age (seven is the age by which most experts believe that magic will reveal itself in a wizard or witch). This, however, would not explain why an adult wizard failed to heal him, though it's possible Rowling's comment referred to the workings of a wizard's magical innate immune system and not to the existence of a wizarding cure for every non-magical malady.
- Sirius was maybe a son of Cygnus Black I and his wife Ella Max, but if this is true, that means Cygnus was 16 years old when he had Sirius. This is possibly a mathematical mistake. If Cygnus was his father, Arcturus Black I was his uncle. His aunt may have been Misapinoa Blishwick (née Black).
- Harry Potter and the Order of the Phoenix (film) (Appears on Black family tapestry)