Fos blight
The fos blight of 649-651 was a vicious fungal disease that affected fos crops throughout the Omban successor states, causing crops to fail across a wide area in successive years. There had always been (and still are) occasional and local outbreaks of various diseases affecting fos crops, but this was the most sustained and widespread, and the one with the most serious political consequences. In particular, the failure of the Basaian fos gardens greatly weakened the position of the Basaian chancellor and the mystics out of Dundures. During this period, fos reserves were almost completely drained. It is generally regarded that the Hasmalan invasions of Basai in the years that followed were motivated by Basai's weakness after the fos blight. It also presaged the general and more widespread decline in fos supplies throughout the Omban successor states in the seventh century.