Fort Raja Mahadi is situated at Bukit Kota in Klang. This fort was actually an arch of the fort. This historic fort is closely related to the history of Klang town. In the olden days, there was a struggle between Raja Mahadi and Raja Abdullah for the control of the Klang district.

Kubu (bahagian dalam) Kota Raja Mahadi Klang

Quarrels among the Batu Bahara ethnic group and the Bugis Melayu ethnic group in the year 1866 intensified the rivalry among Raja Mahadi and Raja Abdullah in Klang.

Kubu (bahagian luar) Kota Raja Mahadi Klang

Raja Mahadi's hatred towards Raja Abdullah was further intensified when Muhammad Akib, from the Batu Bahara ethnic group inform Raja Mahadi that he was ever willing to help him if he wanted to attack Raja Abdullah. This was because Raja Abdullah did not want to punish one of the villager from the Bugis Melayu ethnic group who had murdered one of the villager from the Batu Bahara ethnic group.

Laluan pejalan kaki dibina untuk meninjau sungai Klang di atas Bukit Kota, iaitu kubu Kota Raja Mahadi di Klang.

In the meantime, Raja Abdullah was given the power and authority by Sultan Abdul Samad to control and rule Klang. Raja Abdullah was able to convince the Chinese tin miners to mine in Klang and in return Raja Abdullah was able to get lucrative tin ore from Klang. Hence Raja Mahadi was beginning to get jealous of Raja Abdullah richness and power although Raja Mahadi got a complimentary payment from Raja Mahadi each month.

Keterangan Mengenai Pusara Pahlawan Bugis di atas Bukit Kota, Kota Raja Mahadi Klang.

Therefore when there was a misunderstanding between the Bugis and the Batu Bahara ehnic group and when Raja Abdullah refused to punish the Bugis, Raja Mahadi took this opportunity to seek revenge. Hence the Klang war broke out in 1866 between Raja Mahadi and Raja Abdullah. Raja Mahadi was supported by the Batu Bahara Clan whereas Raja Abdullah and his sons Raja Ismail and Raja Hassan was supported by the Bugis.

Pusara Panglima Raja Mahadi berketurunan Bugis, Muhammad Akib  di atas Bukit Kota, Kota Raja Mahadi Klang.

However, in the beginning of the war the local people were not involved. At that time Raja Mahadi stayed on top of a hill which until today still exist a fort entrance that is, Fort Raja Mahadi. The position of Fort Raja Mahadi was very strategic. This Fort was built on a hill not far from the river. All ships and boats that sailed through to Pangkalan Batu and Gudang Raja Abdullah were easily intercepted.

In order to further strengthened his fort he sought the help of Baba Tek Cheng who was promised a piece of land if Raja Mahadi won the war. With strategic position of the fort he was able to intercept all ships sailing to Raja Abdullah's warehouse.

Keterangan mengenai Kota Raja Mahadi yang dibina pada 1866 dalam dwibahasa.

In the end, the people under the control of Raja Abdullah's sons, Raja Ismail and Raja Hasan faced shortage of food. However, Raja Ismail and Raja Hasan managed to get out of the warehouse to seek assistance for their who were at Melaka.

Raja Abdullah, seteru Raja Mahadi membina Gedung Raja Abdullah, boleh dilihat daripada pintu gerbang ini.

Raja Mahadi has never paid his monthly tax all this while to Sultan Abdul Samad who stayed at Langat and this angered the Sultan. Sultan Abdul Samad decided to take revenge by giving full power to his son in law Raja Kudin to control Klang. Thus, Raja Ismail was supported by Raja Kudin and the people of Kedah in the Klang War against Raja Mahadi. Raja Mahadi was attacked form the land as well as from the river. After several months of fighting and with the food supply getting low, Raja Mahadi quietly retreated from Klang and went to Kuala Selangor. The people of Raja Mahadi also surrendered with the condition that the children and the women were not harmed.

Bukit Kota, di atasnya dibina tembok daripada tanah yang menjadi kubu Raja Mahadi, kini menjadi tapak bangunan Majlis Perbandaran Klang. 

Hence the Fort Raja Mahadi fell into the hand of Tungku Kudin on March 1870 after six months the fort was surrounded and attacked. Sultan Abdul Samad handed over the ruling power of Klang to Tungku Kudin. Fort Raja Mahadi became the fort of defence for Tungku Kudin. However, the fort became unimportant after the war ended.