Why and how did the poverty in sudan started?

Answer 1

The question assumes that we all know what "poverty" means, that "sudan" means the same place through time, and that poverty can be said to have started there.

I'm going to assume that by poverty, you mean less wealthy than the modern standards of the West. To most of the world, that's just normal.

If you're interested in why the modern nation of Sudan is poor, you could start with the thesis of Jared Diamond in the book "Guns, Germs and Steel" - that a few key resources, technological developments and wars tipped the global balance of wealth and power - and that it's not permanent.

Info about Diamond's book here: http://en.wikipedia.org/wiki/Guns,_Germs,_and_Steel

A much shorter explanation that ignores much of history is that Sudan has been embroiled in civil wars and beset by the expansion of the Sahara for most of its history as an independent nation - that is, for over four decades.
General history of Sudan here: http://en.wikipedia.org/wiki/History_of_Sudan

My own thought is that the environment of Sudan and its region has for most of human history supported low-density human habitation. It has few resources, and little ability to control their extraction. The people have developed low-tech methods of living in their harsh environment, but do not have the upper hand in any contacts with the outside world - except when it comes to living in their own environment.

Parts of the region (more than Sudan, the modern country - I'm referring to "the sudan," the region overlapping the Sahara and the dry, non-desert areas to its south) have been wealthy and even fairly powerful, but the states and peoples of the region did not gain power over others and steal their wealth, which is what made the West powerful.
Felipe Fernandez-Armesto can probably e xplain this in lots of detail: http://en.wikipedia.org/wiki/Felipe_Fernández-Armesto

I hope this helps.