Matabeleland does nnot exist in the canon. It is solely the invention of the fanfic writer A.A. Pessimal.
In the Pessinal Discworld:-
Matabeleland is a near-neighbour of Kwazululand. It is situated Rimwards and Widdershins of Kwazululand and is an independent black country, estranged from the Zulus on the basis of long-standing tribal rivalry and neighbourly suspicion, organised on similar social principles with its own Paramount King at the top. While its neighbour is principally veldt, Matabele occupies the jungle belt immediately Hubwards of the URH province of Smith-Rhodesia, and this, together with a vigorous guerilla warrior ethic, explains why the white state has been able to encroach no further.
Intended by Pessimal to be the up-to-eleven Discworld referent for the real Darkest Africa, together with elements of countries like the Congo and Nigeria. In fact, Matabeleland is the home of inventive clacks frauds, such as the Code 419 now being seen by the Watch in faraway Ankh-Morpork..
Prince Samuel, a canonical character, was effectively Prince Regent ruling the country on behalf of his increasingly elderly father, the Paramount King. However, Samuel's corruption and venality have led the nation into deep economic trouble and after the reverse described in the story Let's Bungle in the Jungle, has lost face and prestige to his younger brother Prince Gabriel. At the end of this tale, three states Samuel serially threatened or offended are conspiring to bring about a serious regime change in this nation.