Anzac Day, officially recognized in 1916, emerged as a significant observance for Australia and New Zealand, marking the Gallipoli campaign's impact on national identity. Initially an unofficial holiday, it evolved to honor not just those lost in World War I but all military conflicts. The day celebrates the Anzac spirit, characterized by bravery and egalitarianism, while traditions like the Anzac biscuit reflect the resilience and resourcefulness of those who supported soldiers during the war.