In Harry Potter and the Half-Blood Prince (2005), McGonagall duels with the Death Eater Alecto Carrow during the Battle of the Astronomy Tower. McGonagall is appointed headmistress after Dumbledore's death, but is replaced by Snape when Voldemort takes control of Hogwarts in Harry Potter and the Deathly Hallows (2007).
By that alone, Voldemort had control of Hogwarts by right of the fact that the Ministry funded the school and by extension the school governors. So Snape was appointed Headmaster over McGonagall, probably due to her friendship with Albus and her anti-Death Eater stance.
Dippet served as Headmaster in the 1940s into the 1960s (and possibly the very early 70s).
Following Lord Voldemort's defeat at the hands of her student Harry Potter and the deaths of Headmasters Albus Dumbledore and Severus Snape, McGonagall takes the position of Headmistress.
Professor Marazion succeeded Minerva McGonagall in the post of Head of Hogwarts School of Witchcraft and Wizardry. This individual became Headmaster or Headmistress some time between 2008 and 2017 after Minerva McGonagall went into retirement as she was "getting on a bit".
However, it's generally believed they met during Voldemort's exile in Albania after his failed attempt to kill Harry Potter. Voldemort, weakened and in a spectral form, was hiding in Albania and Nagini, likely already in her snake form as a Maledictus, encountered him there.
However, there's no doubt that Professor McGonagall is the more capable duelist, and she would completely defeat Bellatrix Lestrange in a duel. It's important to remember the ongoing controversial statements by the creator of the Harry Potter franchise.
He viewed Snape as loyal so rather than kill him by his own hand, he gave Nagini the kill. Voldemort believed that Snape had to be killed to make the elder wand work, since Snape killed Dumbledore.
The Emerald Potion, also known as the Drink of Despair, is a mysterious potion which induces fear, delirium, and extreme thirst. The drink cannot be penetrated by hand, vanished, parted, scooped up, siphoned away, Transfigured, Charmed, or made to change its nature in any way. It can only be drained away by drinking.
In order to conjure the avada kedavra curse, you have to want to kill your victim. We all know that Voldemort could easily kill a child without an ounce of remorse... but not Snape. Snape didn't want to kill Dumbledore, and this was why the spell was blue instead of the usual green.
Nope she didn't know. She aimed to damage though Snape never used a spell back at her, all his were to stop her spells hitting him. No she didn't know. The only 2 that knew at that point was Snape and Dumbledore.
In Harry Potter and the Deathly Hallows, Slughorn briefly appears with other teachers assembling to fight Death Eaters. As Snape is now Headmaster, Slughorn has again assumed the post of Head of Slytherin.
Phineas Nigellus Black was known as the worst headmaster Hogwarts had ever seen in the Harry Potter books.
Harry is the heir of Gryffindor, although he had characteristics of both Slytherin (cleverness, resourcefulness, determination) and Gryffindor (bravery, honor, recklessness, chilvary). It is why Harry was able to claim the Sword of Gryffindor.
Hagrid doesn't have a patronus. It's heartbreaking that one of the biggest animal lovers in the series couldn't conjure up the spell to have a protective charm in animal form. In a tweet, Rowling said that Hagrid couldn't produce a patronus because it's a very difficult spell.
She was sorted into Slytherin House at Hogwarts School of Witchcraft and Wizardry and hated her time at the school due to never being given any positions of power. After her time at Hogwarts, Umbridge rose to prominent and influential positions in the Ministry of Magic in the Improper Use of Magic Office.
Because some snakes could sense heat and movement in a way humans could not, Nagini was able to detect Harry and Hermione even when they were under the Cloak of Invisibility. Harry fought with Nagini, and the serpent bit him before coiling herself around Harry to hold him in place for Voldemort.
He trusted snape because snape had proven himself many times before. Voldemort took anyone that was magical and had his own ideas in common during his first crusade.
While Credence is a Dumbledore, he isn't the brother of Albus, Aberforth and Ariana. In fact, he's Aberforth's secret son! Aberforth met Credence's mother the same summer that Albus and Grindelwald met.
George's twin brother, Fred Weasley, was killed when the Death Eaters attacked Hogwarts Castle, so George's life was likely significantly different after Voldemort's defeat. The two were hardly seen without the other before, and neither the books nor movies talk much of how George handled losing his partner in crime.
In both the Harry Potter and the Deathly Hallows book and film, Hedwig dies during the Battle of the Seven Potters. In the book, Hedwig is hit by a random Avada Kedavra and instantly dies. In the movie, Hedwig is killed because she was trying to protect Harry.