November 10, 1945 Surabaya is commemorate as Hero Day (Hari Pahlawan). The Battle began because of the impact of proclamation on 17th August 1945. The battle was fought among Indonesian Pro-Independence soldiers and British and Dutch troops. Before this battle Indonesia had colonized by Dutch for 350 years. You can imagine that how poor Indonesia. Under Dutch colonialism Indonesian was treated as a slave. On the August 17, 1945 a leader of Indonesia proclaimed the independence of Indonesia as a republic.

That Independence got after Japan surrender in the Pacific. The Independence made a vacuums power, both outside and inside of Indonesia. Creating a uncertain atmosphere, but also one opportunity to get the real independence. On 19th September 1945, some of Indonesian raised a Dutch flag on the top of Hotel Yamato (formerly Hotel Oranje) in Surabaya and tore off the blue part of Dutch flag to be Indonesia flag and also killed the leader of Dutch group, Mr. Pluegman.

Over the time Allied Forces came to Surabaya on the end of October 1945. Six thousands of Indian troops also came to Surabaya followed Allied forces to evacuate European Internees. This made the condition become grip. Brigadier A.W.S. Mallaby, a British Brigadier, was travelling to Surabaya to spread the news about the agreement to his troops. When his car approached the British troops post on International building near The Jembatan Merah (Red Bridge), his car was surrounded by Indonesian soldiers. The commander of post was fearing to be attacked by them, Indonesian. Led by Major Venu K. Gopal, they fired to disperse Indonesian soldiers. Certainly, Indonesia soldiers fired back to the British troops. Brigadier was killed in this event. There are two version how Brigadier Mallaby was killed. First, Brigadier Mallaby was killed by a young Indonesian soldier with the shot. Second stated after the shot someone threw a grenade directly into his car, the explosion caused the back seat to ignite and also caused Brigadier Mallaby killed.

Lieutenant General Sir Philip Christison was angered when he heard Mallaby was killed in Surabaya. British ordered Indonesian surrender and also surrender their weapons but Indonesian Ignored it and still forces to get the real independence. At the dawn on November 10,1945 when the Sun just raised, British deployed their power to bombarded Surabaya. From the air, water and land British destroyed Surabaya. It caused many of Indonesian soldiers death and British also.

After this battle in November 1946, the last British troops left Surabaya because United Nation recognized and supported the Indonesia Independence. This battle was commemorated annually as "Hari Pahlawan" (Hero Day).