V. V. Ganeshananthan's Brotherless Night (2023) is a significant historical novel due to portraying the dreadful effects of the Sri Lankan Civil War on normal human beings. The novel focuses not only on the unconcealed aftermaths of war but also the permanent mental and societal influences that continue to disturb people and societies across generations. This research inspects the way collective memory and cultural trauma are depicted in Brotherless Night through the theories of Marianne Hirsch. According to Hirsch, such shocking experiences as war can be dispersed from one generation to another through stories, family accounts, photos, silence, and cultural practices, causing the succeeding generations to come up with unending emotional relations with the incidents they did not visibly bear. This paper is mostly obsessed with the link between individual and collective memory, the consequence of war on cultural identity, the significance of silence and testimony in creating historical realization, and the effect of storytelling as a means for preserving reminiscences that might otherwise be disregarded or annihilated. The results prove that Brotherless Night refers to memory as a shared cultural procedure that relates individual experiences with cooperative history. The novel exemplifies that the trauma of war is not limited to those who went through violence but continues to distress succeeding generations through inherited recollections and emotional bonds.