What happened on the night of Bill and Fleur's wedding?

Question

On the night of the wedding, Kingsley Shacklebolt's Patronus interrupts the reception to warn the merry-makers - most of the Order of the Phoenix - that the Ministry has fallen, the Minister has died, and the Death Eaters are coming.

Two questions:

1. Why did the Ministry have to "fall" in order for Death Eaters to attack the Burrow? Was it just a coincidence that Scrimgeour was murdered the same night as the attack on the Weasleys' house?
2. Unless I am misremembering, wasn't the Burrow protected by a Fidelius Charm, with Arthur Weasley as Secret-Keeper? How, then, could the Death Eaters attack the wedding reception?

Answer 1

Before Harry leaves the Dursley's house when the Death Eaters are discussing their plan of attack:

“Where are they going to hide the boy next?”

“At the home of one of the Order,” said Snape. “The place, according to the source, has been given every protection that the Order and Ministry together could provide. I think that there is little chance of taking him once he is there, my Lord, unless, of course, the Ministry has fallen before next Saturday, which might give us the opportunity to discover and undo enough of the enchantments to break through the rest.”

So it was their belief at the time that if the Ministry were to fall they would have enough knowledge of the enchantments to undo them and overpower the rest.

As far as Arthur being the Secret-Keeper, it does not appear that the Burrow was protected by the Fidelius Charm. Scrimgeour at least arrived seemingly without an invitation. You might be getting confused with a part later in the book, when Harry arrives at Bill and Fleur's house, Bill then explains that they moved everyone out of the Burrow to their aunt Muriel's, and that their dad was Secret-Keeper there.

Answer 2

• My understanding was (though no quotes to back it up) that the wedding reception was not in the Burrow itself (which WAS protected by Fidelius) but at a orchard near the property.

• "Why did the Ministry have to "fall" in order for Death Eaters to attack the Burrow?"

  Two likely reasons:

  1. Before the Ministry fell, presumably the Ministry and Aurors would have reacted to the attack on the Burrow against DEs.

  2. It's possible (though no canon support) that being in charge of the Ministry allowed DEs to be more effective in breaking some protections - we know for sure Ministry can do things normal wizards can not (trace Apparations, trace underage or other use of magic) and has access to some very unique and powerful artifacts.

To be honest, there's pretty thin canon support for this I can think of - the wedding and reception and fall of the ministry were not addressed by JKR in any interviews that I could find.

Answer 3

The Burrow was protected.

But when the Ministry "fell" the Death Eaters had control over any protection charms and could easily get through them.

That is also how the evil Ministry now knew and could find all people who apparated or who said Voldemort's name.

Answer 4

The reason why the Ministry fell during the wedding is that the defenses at the Ministry were lower at that time. In DH ch. 9, Ron says ‘Most of the Order was there’ in the wedding. The Weasly family, Tonks, Lupin, Hagrid, Elphias Doge together account for a large part of the Order, and they were all at the wedding, many of them drinking.