Kamboh is frequently used as surname or last name by Muslim Kambojs, currently living in Pakistan.
Origin of word
The word Kamboh is a derived from the combination of two terms Kai & Amboh. Amboh means 'a following' 'a family', or 'large gathering'. Kai was a royal dynasty of Persian traditions. Thus Kai plus Amboh =Kaimboh=Kamboh means the royal family of Kai kings. Thus the Kambohs claim to have descended from the kings of line Kais of the Ancient Persia. .
According to Dr Carry, Kai was a king of Persia who was connected with the royal Kai dynasty which ruled Persia before Dara (Darayvaush or Darius). The royal title Kai frequently finds mention in the Hindu traditions also. This Kai was one of the well-known titles among the ancient royal dynasties of Persia. Kai-kam-bakash was the Greek Cambysis or O.P Kambujiya or Kambaujiya (Kamboja of Sanskrit literature) according to Persian traditions. .
The first emperor of Kai dynasty was Kai-Kabad. He ruled in Persia and his Capital was Persipolis. He ruled for 15 years. He was followed by his son Kai-Kaus. Son of Kai-Kaus was married to princess of Turan (Central Asia), a daughter of king Afrasyab. The result of this marital union was the birth of a great king Kai-Khusro who later ruled over Persia. According to interprettations of Historians, Kai-Khusro was the successor of Darius I. The names for these Achamenian kings as appear in Greek are very much corrupted form of actual names of Persian and Hindu traditions. As is stated above the kings of Kai dynasty of the Persian traditions correspond to those from the Achamenian dynasty of the Greek writings and that of O.P Inscriptions. Further, numerous scholars have related the Achaemenian kings to the Persian Kambojas.
Kai Khusro was the this king of Kainid Dynasty. He was the grandson of Kai Kausand son of Siyavush. Name of this king Kai-Khusro is included among the list of most righteous kings and also finds mention in the 8th Hakayat .
"Rustam placed on throne the founder of a new dynasty that of the Kais, so called because every king's name is preceded by Kai. The traditional Kais correspond roughly to the historical line of Achamenids or Achamenian Persian dynasty for they end with the conquest of Alexandrera" 
Thus from above, the legendary warrior Rustam & his son warrior Suharab belonged to the Persian Kambojas of Kai or Achamenian line. The great warrior Rustam has been described as the shield of Persia.
Thus according to the above view, the Kai was indeed a royal title in Persian traditions for many of kings who correspond roughly to the royal line of the Achamenian kings of Greek writings with whom the Kambojs might indeed be connected through their tradition (Kai+Amboh=Kaimboh=Kamboh).
- The Sikhs, by A. H. Bingley, 1970, Language Department, Punjab, p 57, A Glossary of Tribes & Castes,, II, pp 442 ff, Supplementary Glossary p 304, Tarikh-I-Kambohan, p 302 Chaudhury Baha-vu-din, Kamboj Itihaas by Jagan N. Sandhey, Encyclopedia of Sikh Religion & Culture by Romesh Chander Dogra, Dr. Gobind Singh Mansukhani, 1997, p 247.
- Annals and Antiquities of Rajasthan, Vol I by Lt Col James Tod, 1960, p 65
- Mahan Kosh 1974, p 348 by Bhai Kahan Singh ji
- Ancient Persia & Iranian Civilization by Clement Huart, 1972, p 208, p 210