Once Upon A Winter began in Thessaloniki, Greece, as a solo Post-Rock project by Ilias Kakanis, releasing their debut album in 2017. What started as a solo effort grew into a full band as the songs demanded more voices to bring them to life. Their sound moves between classic post-rock atmospheres and gothic, doom, and black metal eruptions, with the melodic lines remaining the center of attention, a balance described as having "really mastered the paralleling of heavy and soft soundscapes to the extent that both can uplift and heighten emotions, but can also recede and pacify at any given place and time".

Over the years, Once Upon A Winter built a steady live presence, with headlining shows in various Greek cities, a European tour through Germany, Switzerland, and Italy, a support slot for God Is An Astronaut in their hometown, and opening slots for Deafheaven (2022) and Alcest (2024) in Athens.