He was undoubtedly clever…

A brilliant Charms teacher, Flitwick was also a highly creative thinker. He taught Hogwart’s front doors to recognise a picture of Sirius after his escape from Azkaban, used his abilities to create beautiful Christmas decorations and – according to Lockhart, at least – knew more about Entrancing Enchantments than anyone. Like Hermione (who always gained a lot of praise from Flitwick), he also seemed able to retain a lot of information, if his explanation of the Fidelius Charm is anything to go by:

‘An immensely complex spell… involving the magical concealment of a secret inside a single, living soul. The information is hidden inside the chosen person, or Secret-Keeper, and is henceforth impossible to find – unless, of course, the Secret-Keeper chooses to divulge it.'

… but he was also wise

You’d expect the Head of Ravenclaw to be intelligent, but Flitwick had a wisdom that went beyond cleverness. Whilst some of his fellow Ravenclaws (cough Lockhart cough) could be arrogant, Flitwick was modest. He even left the overseeing of Hogwart’s Duelling Club in Harry’s second year to Lockhart and Snape, despite apparently being a former duelling champion.

He was clearly trusted by Dumbledore to a high degree – contributing enchantments to protect the Philosopher’s Stone, touring the maze in the Triwizard tournament – and although he was never boastful, he had a quiet and enduring confidence in his own abilities. When Professor Umbridge sat in on his lesson during her time as Hogwarts High Inquisitor, Fred remarked:

"Umbridge just lurked in the corner making notes on a clipboard. You know what Flitwick's like, he treated her like a guest, didn't seem to bother him at all.”

He was witty…

In fact, Flitwick was so unbothered by Umbridge he was happy to undermine her when circumstances called for it – particularly when it came to the Weasley twins’ and their magical box of tricks:

‘Thank you so much, Professor!’ said Professor Flitwick in his squeaky little voice. ‘I could have got rid of the sparklers myself, of course, but I wasn’t sure whether or not I had the authority.’

He seems to have reserved this kind of modest-but-still-sarcastic commentary for terrible Defence Against the Dark Arts teachers. Lockhart also felt the impact of Flitwick’s impatience when Ginny was taken into the Chamber of Secrets – Flitwick was one of the first to suggest Lockhart should make good on his boasts and rescue Ginny himself.

… but he was supportive

With his students, though, Flitwick’s calm approach made him very approachable. He was certainly less strict than his fellow Heads of House, allowing classroom games at Christmas and rarely giving out punishments. He clearly also felt a strong responsibility for those in his House – even after being Stupefied and knocked out by a Death Eater, he insisted on returning to look after his Ravenclaws.

And it wasn’t just his own House that he cared about. Flitwick burst into tears when Ginny Weasley was taken into the Chamber of Secrets, forgave Neville for moving him around the room during a Banishing Spells lesson, showed such admiration for Fred and George’s Portable Swamp that he left a section of it in place, and expressed his support for Harry following his Quibbler interview with a surreptitious box of sugar mice. Basically, if you weren’t a terrible Defence Against the Dark Arts teacher, he was pretty supportive.

And he showed great leadership

He might have been small in stature, but Flitwick was always brave – the Sorting Hat did nearly put him in Gryffindor, after all. Not only did he refuse to stay in the hospital wing after being attacked by Death Eaters, he also returned to Hogwarts after Dumbledore’s death to help keep his students safe.

And when it came to the Battle of Hogwarts itself, Flitwick – so small he could barely see over the window frame – was a crucial part of the school’s defence:

‘Minerva!’ said a squeaky voice, and looking behind him, still shielding Luna from flying spells, Harry saw Professors Flitwick and Sprout sprinting up the corridor towards them in their nightclothes, with the enormous Professor Slughorn panting along at the rear.

‘No!’ squealed Flitwick, raising his wand. ‘You’ll do no more murder at Hogwarts!’

Flitwick’s spell hit the suit of armour behind which Snape had taken shelter: with a clatter it came to life. Snape struggled free of the crushing arms and sent it flying back towards his attackers: Harry and Luna had to dive sideways to avoid it as it smashed into the wall and shattered. When Harry looked up again, Snape was in full flight, McGonagall, Flitwick and Sprout all thundering after him: Snape hurtled through a classroom door and, moments later, Harry heard McGonagall cry, ‘Coward! COWARD!’

Essentially, he was the perfect mix of Gryffindor bravery and Ravenclaw wit and wisdom – really, could you ask for a better Head of House than Professor Filius Flitwick?