The continent of Howandaland is not to be confused with Howondaland (the country).
The continent of Howondaland has now ceased to exist; it was the larger of the two landmasses formed after the supercontinent of Pangola split in two, hundreds of millions of years ago. The other was Lauragatea.
Howondaland eventually became The Unnamed Continent in the centre of The Discworld and Klatch.
It was named by the wizard Venter Borass after the country where most of his research was carried out.