"The great Malhamah, the conquest of Constantinople, and the coming of the Dajjal occur in (the span of) seven months."  

عَنِ النَّبِيِّ ﷺ قَالَ الْمَلْحَمَةُ الْعُظْمَى وَفَتْحُ الْقُسْطَنْطِينِيَّةِ وَخُرُوجُ الدَّجَّالِ فِي سَبْعَةِ أَشْهُرٍ  

"Constantinople will be conquered with the coming of the Hour."  

فَتْحُ الْقُسْطُنْطِينِيَّةِ مَعَ قِيَامِ السَّاعَةِ