There has been great tension between Earth and the Minbari ever since they first met. The Earth captain who encountered a strange and unknown ship was carrying the Minbari's great religious and political leader, Dukhat. The Human captain paniced, and opened fire, heavily damaging the ship and bringing about the death of Dukhat.
That event marked the beginning of the Earth - Minbari War, one which the human race almost lost. The Minbari were days away from invading Earth, but suddenly, the Minbari surrendered. No one really knows why the this happened, but apparently something of great importantance must have occured in order for them to call for peace on the eve of their victory.
Since that time, relations between the Minbari have improved greatly, although it is still somewhat touchy. The strong bond between Captain Sheridan and Delenn have made the relationship between the governments much more favorable, so much that several Minbari cruisers were assigned to Babylon 5 to defend it as part of the Babylon 5 Defense Treaty.
However, troubles on Minbari have arisen ever since Delenn dissolved the Grey Council and the 3 castes began to compete against one-another. The warrior caste has reportedly started to form their own council with the hopes of seizing complete power of the other 2 castes. The religious caste, although armed with some White Star ships, is seriously outmatched militarily. Delenn is returning to Minbar in an effort to prevent what could escalate into a civil war.
"Information concerning the two Minbari representatives to Babylon 5 can be found here:"
"The following links are regarding various Minbari spacecraft."