Intro
Mirza Ghulam Ahmad purposely mixed up the concept of the Mahdi in Islam, and the term “Mahdi”.  The term Mahdi simply means anyone guided…and as we all know…every Mujadid in Islam could also be referred to as a Mahdi.  However, there is a specific “Mahdi” who will show up on Earth and lead an islamic govt. to victory and etc etc etc.  In islamic history, some scholars have written about this….Sunni only…not Shia.  The Shias have an entirely different concept, I dont promote it nor do I ever quote any Shia books like “Dar-e-Qutni”.

The reference from Najamul-Huda (1896)

The reference, see page 3

http://aaiil.org/text/books/mga/najmulhuda/najmulhudastarguides.shtml