Over generations, Matrak had been able to develop a very comprehensive battle strategy against their western neighbors- the Thesian city states.
By mixing geography and unique terrain features with their own battle tactics, Matrak had shown themselves to be too hard a nut to crack, thus effectively blunting all their neighbor's grand ambitions.
The city states also, after many repeated ambitions came to the realization that this province was not worth the cost. They found their prided heavy infantry had a tough time facing off the ubiquitous mobile cavalry in an open battlefield, repeatedly getting outflanked, surrounded, and destroyed.
In recent years, Pasha Farzah further solidified those borders by cutting a deal with Exolas and its alliance of city states, promising them to help annex their rival Cantegena in exchange for a stable border with him.