Datuk Siamang Gagap

{{Expand Indonesian|topic=bio|Datuk Siamang Gagap|date=June 2017}}

{{Infobox person

|name = Datuk Siamang Gagap

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|birth_name = Abdul Kahar bin Mukmin

|birth_date = {{birth year|1817}}

|birth_place = Kampung Repah, Tampin, Negeri Sembilan

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|death_place = Either Juasseh, Negeri Sembilan or Pahang, British Malaya

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|other_names = Pendekar Siamang Gagap

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|relations = Adnan Saidi (great-grandson)
{{Cite book|title=Leftenan Adnan Wira Bangsa|first=Abdul Latip|last=Talib|publisher=Mika Cemerlang Sdn. Bhd.|isbn=9789670148908|location=33-1 Jalan USJ 1/1A, Regalia Business Center, 47620 Subang Jaya, Selangor, Malaysia.|pages=23–25}}

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Abdul Kahar bin Mukmin (born 1817 - unknown), who is better known as Datuk Siamang Gagap, was a folk hero from Negeri Sembilan, Malaysia. A hulubalang and a palace official in Seri Menanti during the reign of Yamtuan Antah, he is known for his involvement in the resistance movement against the British in the Battle of Bukit Putus.