The Danishmendid emir recaptured Kastamon while Ioannes II was ill in Constantinople

The defeated Danishmendid ruler of Kastamon besieged the city he had once ruled and captured it, slaughtering the Byzantine defenders. This demanded the reaction of Ioannes II, who was probably ill at the key moment 
Gümüshtegin Ghazi, second ruler of Danishmend dynasty (Gumushtegin 101)
  • He gathered a large force and besieged and captured Kastamon, slaughtering its Byzantine defenders; however, soon afterwards he died (:) Niketas Choniates, Historia 19.6-9
  • Besieged Kastmon and starved it into submission (:) Kinnamos 14.4-9
Emperor Ioannes II Komnenos (Ioannes 2)
  • Fell sick and was conveyed back to Constantinople at the time of death of his wife (Eirene 62). He was also very dismayed by Gumushtegin 101’'s recapture of Kastamon (:) Kinnamos 14.7-10