The Yeoman Warders - the Beefeaters - have their own accommodation in the Tower's Outer Ward and they have also their own pub:

https://en.wikipedia.org/wiki/Yeoman_Warders_Club

They should call it The Queen's Head

Why?

It's a slightly-tasteless joke resting on two facts:

1. The [King's / Queen's] Head is a common pub name in the UK.

2. Several queens have been executed by beheading at the Tower of London.

3. The word "head" in a nautical context also refers to the ship's toilet.

4. Beer head is also another name for the foam

Divorced.

Beheaded.

Died.

Divorced.

Beheaded.

Survived.

What does that mean?

It is what happened to each of the wives of King Henry the 8th. It's a famous rhyme intended to make it easy to remember the order of what happened to them: https://en.wikipedia.org/wiki/Wives_of_Henry_VIII

> What happens to the barrel of fine alcoholic drink after it gets handed to the Constable?

It is imbibed:

* https://www.youtube.com/watch?v=xAS9j1BWGiE&t=1m44s