From Wikipedia & Malaysiana1.
Negeri Sembilan Darul Khusus (Special Land) is located on the western coast of Peninsular Malaysia and is bordered in the north by Selangor, in the east by Pahang and in the south by Melaka and Johor.
Its name literally means 9 Districts. Its indigenous Sungai Ujungian or Minangkabau people formed the kingdom of Minangkabau in Indonesia’s modern-day province West Sumatra, before migrating back to the Malaysian mainland in the 1400s.
Formerly part of Selangor, and thus a protectorate of Johor, Negeri Sembilan became a separate kingdom in 1773 under the rule of Minangkabau prince Tuanku Melewar.
It was acquired by the British in 1875 and gained independence as a state of Malaysia on August 31, 1957.
The capital of Negeri Sembilan is Seremban while Kuala Pilah is the royal town. Other major towns are Port Dickson and Bahau.
Negeri Sembilan’s population is 55 per cent indigenous Malaysian (mostly Minangkabau), 24 per cent Chinese and 21 per cent Indian.
The state has a mainly agricultural economy with oil palm, rubber and tropical fruits as its major cash crops. The state is fast becoming a centre of small and medium scale industries.
The state is divided into seven districts namely Seremban, Port Dickson, Rembau, Tampin, Kuala Pilah, Jempol (Bahau) and Jelebu (Kuala Klawang).
It originally had 9 districts namely Sungai Ujung (Seremban), Rembau, Tampin, Johol (Kuala Pilah), Jempol (Bahau), Jelebu (Kuala Klawang), Teraci (in Kuala Pilah), Hulu Muar (in Kuala Pilah) and Gunung Pasir (in Kuala Pilah).
Port Dickson was originally in Selangor but was ceded to Negeri Sembilan in 1895.
Negeri Sembilan's ruling monarch is titled Yang Dipertuan Besar, which literally means Great King.