harry potter - How and when was the statue head Portkey to Hogwarts set up?

After the battle in the Ministry, Professor Dumbledore sends Harry to Hogwarts using a Portkey. The Portkey is a part of the statue in the "Fountain of magical brethern" in the atrium of the Ministry of Magic, and sends Harry to the Hogwarts headmaster's office. Quoting Harry Potter and the Order of the Phoenix chapter 36.

He [Dumbledore] walked away from the pool to the place where the golden wizard's head lay on the floor. He pointed his wand at it and the muttered, ‘Portus.’ The head glowed blue and trembled noisily against the wooden floor for a few seconds, then became still once more.

‘Now see here, Dumbledore!’ said Fudge, as Dumbledore picked up the head and walked back to Harry carrying it. ‘You haven't got authorization for that Portkey! You can't do things like that right in front of the Minister for Magic, you – you –’

Did Professor Dumbledore set up the Portkey then and there? Or was it instead a Portkey set up previously, and he merely activated it with that “Portus” incantation?

Hogwarts had magical protection set up so you can't easily enter using a Portkey. If Professor Dumbledore quickly set up the Portkey right there and then, how did he get past the protection? If the Portkey had been set up previously, did they make sure it couldn't be misused to breach the security of Hogwarts?

See also Who can make a portkey that goes into Hogwarts? and In Harry Potter and the Order of the Phoenix it seems Dumbledore makes a portkey that only Harry can use. Am I interpreting this correctly?

Answer

When did Dumbledore set up the Portkey?

It seems that the Portus charm creates a Portkey at the point of casting. We see Dumbledore use it earlier in the same book:

Dumbledore was now rummaging in a cupboard behind Harry and Ron. He emerged from it carrying a blackened old kettle, which he placed carefully upon his desk. He raised his wand and murmured “Portus”; for a moment the kettle trembled, glowing with an odd blue light, then it quivered to a rest, as solidly black as ever.

— Order of the Phoenix, chapter 22 (St. Mungo’s Hospital for Magical Maladies and Injuries)

Unless Dumbledore was extraordinarily prescient and negligent, there’s no way that he could have foreseen the need for this Portkey. It follows that Portus is creating a Portkey.

Thus, Dumbledore must be turning the head into a Portkey at the point of casting Portus; he wasn’t activating a pre-existing Portkey.

Also note that the statue was only decapitated when Harry was fighting Bellatrix. Once Dumbledore arrives, he’s engaged with fighting Bellatrix and Voldemort. When would he have turned the head into a Portkey? He certainly wouldn’t stop mid-duel to do it.

How did he set it up?

Using the Portus charm.

(The HP Wiki has a screenshot from the Charms O.W.L. in the Order of the Phoenix movie which identifies this as a charm.)

How did Dumbledore get past the Hogwarts protections?

Dumbledore is the school headmaster, and set up many of the protections around the school. It seems logical that he can likewise undo them. As he says in the Half-Blood Prince film, “Being me has its privileges”. There are other canon examples of Dumbledore undoing the school protections:

• Creating a Portkey for Harry and the Weasleys in Order of the Phoenix, during the incident quoted above. This has to leave Hogwarts.



• Raising the anti-disapparation jinx from the Great Hall so that students can practice.


• Undoing the protective enchantments as he flies over the boundary with Harry at the end of Half-Blood Prince.

So presumably Dumbledore can create a Portkey to penetrate the Hogwarts defenses, but nobody else can.