Territorial Defense Day is observed in Ukraine every first Sunday of October. Established by President Volodymyr Zelensky’s decree in September 2020, the day highlights the importance of territorial defense in ensuring Ukraine's national defense capability and territorial integrity, particularly in light of the ongoing War in Donbass. The day serves as a reminder of the state's priorities in achieving peace and preserving sovereignty. The formation of territorial defense battalions began in 2014 following the annexation of Crimea, with these volunteer units initially created to assist in protecting the state border and maintaining law and order. Over the years, these battalions evolved into independent motorized infantry battalions and were restructured into territorial defense brigades across all oblasts of Ukraine, which also engage in emergency response and organize resistance movements in case of enemy occupation.