There once was this kingdom with the following properties:

1.) The kingdom was small: any person in the country could meet all others in
one day.

2.) The citizens of the kingdom were extremely loyal to their King, and would
obey him unquestionably.

3.) The laws of physics were a little strange in the kingdom, in such a way
that no one person in the kingdom could tell how (s)he looked (but could see
how others looked).

4.) A standing law in the kingdom stated that citizens were forbidden to
discuss their appearance with others, in any conceivable direct or indirect
way.

5.) The king was never misinformed, and never lied.

One day, the King made an announcement to his subjects:

"It has come to my attention that some people in the kingdom have blue eyes.
Having blue eyes is a sign of demonic possession.
From this day forth, I make the following decree: should any of you discover
that you have blue eyes, you should immediately commit suicide."

Exactly twenty eight days after the announcement, all the blue eyed people
in the kingdom were dead.

How many blue eyed people were there in the kingdom?