The night of Miraj was a miraculous journey that Prophet Muhammad صَلَّى اللّٰهُ عَلَيْهِ وَسَلَّم took in one night from Makka to Jerusalem and then an ascension to the heavens.
Muhammad Raza Saqib Mustafai explains how Allah سُبْحَانَهُ وَ تَعَالَى welcomed his beloved Rasul Allah صَلَّى اللّٰهُ عَلَيْهِ وَسَلَّم on Isra (the night journey).
According to some of ahadith and scholars, this journey is believed to have taken place just over a year before Prophet Muhammad صَلَّى اللّٰهُ عَلَيْهِ وَسَلَّم migrated from Makka to Madina, on the 27th of Rajab.