The Battle of Surabaya was a battle of pro-independence Indonesian soldiers and militia and British and British Indian troops. The climax occurred on November 10, 1945. This battle was the first war between Indonesian troops and foreign troops after the Proclamation of Indonesian Independence and one of the biggest and heaviest battles in the history of the Indonesian National Revolution which became a national symbol of Indonesia's resistance to colonialism. After this battle, the support of the Indonesian people and the international community for the struggle for Indonesian independence grew stronger. November 10 is celebrated annually as Heroes' Day in Indonesia.

When Allied forces landed in late October 1945, Surabaya was described as "a strong united fortress [under Youth]". Fighting broke out on 30 October after the commander of British forces, Brigadier A. W. S. Mallaby was killed in a gun battle. The British launched a punitive counterattack on 10 November with the assistance of warplanes. Colonial troops captured most of the city in three days, armed Republicans fought back for three weeks, and thousands of people died when city dwellers fled to the countryside.

Even though they were defeated and lost their members and weapons, the battles that were waged by the Republican troops aroused the enthusiasm of the Indonesian people to fight for its independence and attracted international attention. The Netherlands no longer saw the Republic as a bunch of messengers without popular support. This battle also convinced Britain to take a neutral stance in the Indonesian national revolution; several years later, Britain supported the Indonesian struggle at the United Nations

and there's the reason why "Battle of Surabaya" happen

1.Arrival of British & Dutch Soldiers
After the defeat of the Japanese, the Indonesian people and fighters attempted to disarm the Japanese soldiers. So there were battles that took casualties in many areas. When the movement to disarm Japanese troops was flaring up, on 15 September 1945, British troops landed in Jakarta, then landed in Surabaya on 25 October 1945. British troops came to Indonesia to join AFNEI (Allied Forces Netherlands East Indies) on behalf of and on behalf of The Allied Powers, with the task of disarming the Japanese army, freeing prisoners of war held by the Japanese, and repatriating Japanese troops to their country. But apart from that the British soldiers who came also carried the mission of returning Indonesia to the Dutch administration as a colony of the Dutch East Indies. NICA (Netherlands Indies Civil Administration) joined a group of British troops for this purpose. This triggered upheaval of the Indonesian people and gave rise to resistance movements of the Indonesian people everywhere against the AFNEI army and the NICA government.

2.The incident at the Yamato Hotel, Tunjungan, Surabaya
After the appearance of the Indonesian government's announcement dated August 31, 1945, which stipulated that starting September 1, 1945, the national flag of Sang Saka Merah Putih was being hoisted all over Indonesia, the flag-raising movement spread to all corners of the city of Surabaya. The climax of the flag-raising movement in Surabaya occurred at the tearing of the flag at the Yamato Hoteru / Hotel Yamato (named Oranje Hotel or Hotel Orange in colonial times, now known as Hotel Majapahit) on Jl. Tunjungan no. 65 Surabaya.

A group of Dutch people under the leadership of Mr. W.V.Ch. Ploegman on the evening of 18 September 1945, precisely at 21:00, raised the Dutch flag (Red-White-Blue), without the approval of the Surabaya Regional Government of Indonesia, on the pole at the top level of the Yamato Hotel, north side. The next day the Surabaya youth saw him and became angry because they thought the Dutch had insulted Indonesian sovereignty, wanted to restore power to Indonesia, and harassed the Red and White flag-raising movement that was taking place in Surabaya.
Shortly after the mass gathering at the Yamato Hotel, Resident Sudirman, fighters and diplomats who at that time served as Deputy Resident (Fuku Syuco Gunseikan) who were still recognized by the government of Dai Nippon Surabaya Syu, as well as the Resident of the Surabaya Regional Government of the Republic of Indonesia, came through the crowd and entered Sidik and Hariyono escorted to Hotel Yamato. As the RI representative, he conferred with Mr. Ploegman and his friends and asked that the Dutch flag be immediately removed from the Yamato Hotel building. During these negotiations Ploegman refused to lower the Dutch flag. The negotiations heated up, Ploegman pulled out a gun, and a fight broke out in the negotiating room. Ploegman was strangled to death by Sidik, who was later killed by Dutch soldiers on guard and heard Ploegman's gun fire, while Sudirman and Hariyono fled outside the Yamato Hotel. Some youths scrambled to get to the top of the hotel to lower the Dutch flag. Hariyono, who was with Soedirman, returned to the hotel and was involved in climbing the flagpole and together with Koesno Wibowo succeeded in lowering the Dutch flag, tearing off the blue part, and hoisting it to the top of the flagpole again as the Red and White flag.

After the incident at the Yamato Hotel, on October 27, 1945, the first battle broke out between Indonesia and the British army. These small attacks later turned into general attacks that claimed many lives on both the Indonesian and British sides, before finally General D.C. Hawthorn asked President Sukarno for help to Silent the situation.

3.Death of Brigadier General Mallaby
After the ceasefire between the Indonesian side and the British army was signed on 29 October 1945, the situation gradually subsided. Even so, there were still armed clashes between the people and the British army in Surabaya. The armed clashes in Surabaya culminated in the killing of Brigadier General Mallaby, (the leader of the British army for East Java), on 30 October 1945 at around 20.30. Brigadier General Mallaby's Buick car ran into a group of Indonesian militias as they were about to pass Jembatan Merah. The misunderstanding led to a shootout which ended in the death of Brigadier General Mallaby by the gunshot of an unidentified Indonesian youth, and the car was burnt by a grenade explosion which made Mallaby's body difficult to identify. Mallaby's death caused the British to be angry with the Indonesians and resulted in the decision to replace Mallaby, Major General Eric Carden Robert Mansergh, to issue an ultimatum on November 10, 1945 to ask the Indonesians to surrender weapons and stop resistance to the AFNEI army and the NICA administration.

and that's make "Battle of Surabaya" Begin right in "10 November 1945"
After the killing of Brigadier General Mallaby, his successor, Major General Robert Mansergh issued an ultimatum which stated that all Indonesian leaders and armed Indonesians had to report and put their weapons in the designated place and surrender by raising their hands above. The ultimatum limit was 6:00 am on November 10, 1945.

The ultimatum was later seen as an insult to the fighters and the people who had formed many struggle / militia bodies. The ultimatum was rejected by the Indonesian side on the grounds that the Republic of Indonesia was already established, and the TKR (People's Security Army) had also been formed as a state force. In addition, there were many armed struggle organizations that had been formed in the community, including among youths, university students and students who opposed the re-entry of the Dutch government, who piggybacked on the British army in Indonesia.
On the morning of 10 November, British troops began launching attacks. Allied forces received resistance from Indonesian troops and militias.

Apart from Bung Tomo there were also other influential figures in moving the people of Surabaya at that time, some of whom came from religious backgrounds such as KH. Hasyim Asy'ari, KH. Wahab Hasbullah and other pesantren kyai also mobilized their students and civilians as resistance militias (at that time the people were not so obedient to the government but they were more obedient and obedient to the kyai / ulama) so that the Indonesian resistance was tough, from day to day, to from week to week. The people's resistance, which was initially carried out spontaneously and not coordinated, was getting more and more organized. This battle lasted about three weeks.

At least 6,000 - 16,000 fighters from the Indonesian side were killed and 200,000 civilians fled from Surabaya. British and Indian casualties were roughly 600-2000 soldiers. The bloody battle in Surabaya that claimed thousands of lives has stirred up popular resistance throughout Indonesia to take up resistance. The number of fallen fighters and civilians who became victims on November 10 was later remembered as Heroes' Day by the Republic of Indonesia until now.

yeah it seems i late for post this right in time
even because my life is hard now