Rosier

"...-Nott, Rosier, Mulciber, Dolohov- waiting for your return... What devoted friends, traveling so far away in the snow and the night just to wish you good luck in trying to get a teacher position."

- Albus Dumbledore to Tom Riddle.

Rosier was a wizard, possibly a Slytherin student at Hogwarts School of Witchcraft and Wizardry and one of the earliest Death Eaters of Lord Voldemort. He was possibly the father of Evan Rosier. He fought in the First Wizarding War, and travelled to Hogsmeade in order to "wish good luck" to Tom Riddle in trying to get a teacher position at Hogwarts. It is possible that Rosier was deceased before the start of the Second Wizarding War, but, if he was not, he possibly fought at the Battle of Hogwarts and was presumably killed or imprisoned in Azkaban after Voldemort's final defeat.

Early life
Rosier might have attended Hogwarts at the same time with Tom Riddle, and he may have been a member of Slytherin house, as well as a member of Tom Riddle's gang and the Slug Club. After Hogwarts, Rosier became one of the earliest Death Eaters. It is possible that Druella Rosier, wife of Cygnus Black III is his sister, and, if Evan Rosier was his son, it is possible that his son was named after himself.

First Wizarding War
Rosier fought in the First Wizarding War along with many other Death Eaters. He was also one of the Death Eaters who travelled to Hogsmeade, "to say good luck to Voldemort, during his attempt to ask for work at Hogwarts, along with Nott, Mulciber and Dolohov. It is possible that he was the father of Evan Rosier, who attended Hogwarts with Severus Snape in the 1970s, and who was killed by Aurors in the end of the First Wizarding War. After Voldemort's first downfall, Rosier was presumably killed, imprisoned or defected. If he survived it is most likely that he was one of the Death Eaters who did not search for Voldemort.

Second Wizarding War
It is unknown if Rosier was still alive during the Second Wizarding War; if he was, he possibly fought in several battles, including the Battle of Hogwarts.

Post-war
After Voldemort's final defeat, Rosier was presumably went into hiding, was killed or imprisoned in Azkaban, assuming he was not already dead.

Appearances

 * Harry Potter and the Half-Blood Prince