I have done something wrong but I don't know what.

This is how the svg file looks in Inkscape: http://s304.photobucket.com/albums/nn177/Ptolemeus/?action=view&current=Yarmouk.png

And it looks exactly how I want it to.
But when I save it, it looks like this: http://s304.photobucket.com/albums/nn177/Ptolemeus/?action=view&current=Yarmouk1.png

The problem is probably opacity but I don't know what I did wrong and what I can to fix it.

I think it's just the background: Inkscape lets you set a background colour, but as far as SVG is concerned the background is still transparent.

So, turn off the Inkscape background colour, and add a rectangle of the appropriate colour behind everything else.

It worked. http://en.wikipedia.org/wiki/File:Battle_of_Yarmouk_Map.svg. But I think it is a bit weird.
Thank you for answering.

whats weird? map looks beautiful to me.

Yes, the map worked out well but the solution to the problem: putting a rectangle behind the map in order to make it perfect.