The highest mountain on the Australian continent (though on the neighboring islands there are some higher peaks) was discovered and named Mount Kosciusko in 1840 by the Polish explorer Sir Paul Edmund de Strzelecki.
CB - (Companion of the Bath) - 21 November 1848;
FRS - Fellow of the Royal Society - June 1853;
DCL - (Doctor of Civic Law) - 20 June 1860;
KCMG - (Knight Commander of St Michael and St George) - 13 June 1869;
FRGS - (Royal Geographical Society)
... such a spelling was used in English by Strzelecki himself, which shows on the maps prepared by him, and also in the report about the exploration of Gippsland. This was not a mistake but just a simplification making the pronunciation easy, which was proper and often practical in previous centuries.
Thaddeus Kosciuszko himself quite often skipped the letter „z” in his signature. Also a book by him, published in 1808 in New York, bears the title „Maneuvers of Horse Artillery by General Kosciusko”.
In 1851 the colonial geodesist T. Townsend officially placed the name Mount Kosciusko on maps of Australia and, officially, the name stayed unchanged to 1997, when with the endeavor of Poles, on the occasion of 200 anniversary of P.E. Strzelecki's birth, the State (NSW) Geographic Names Board resolved that the name ought to be supplemented with the letter „z”.
Nowadays the highest peak of the Australian continent bears the official name Mount Kosciuszko. Successively the new form is being introduced on the ground of The National Park, in names of streets etc.
And this is the legal history of the Mount Kosciuszko's name.
Officially there were no other names, but in the period over 150 years since the exploration of the mountain, various menders of the history of the known class: „discoverers”, „research workers”, „authors”, often attempted the assassination of the mountain: tried to push it into another place, to change the name etc., but „Kozyosko” and „Strezleki” have managed to defend themselves.