This range is about 2,400 km long enclosing an area that starts almost from the Indus and ends close to the Brahmaputra, with a gap of about 90 kms between the Teesta and Raidak rivers in Assam.
- Inscriptions as well as old historical chronicles connect Chauhans with Jangaladesha and Sapadalaksha. 
- The Kumarikhanda of the Skanda Purana which mentions a few other Sapadalaksha, i.e., territorial units supposed to have 1-1/4 lac villages. The Chauhans belonged to the Sakambhara-sapadalaksha which probably is the territorial unit meant by Wasaf who writes that "Siwalik contains 1,25,000 towns and villages." (ED., III, p. 31.).
- (a) "Again, he (Muhammad Bahlim) rebelled, and founded the fortress of Naghawr, in the territory of Siwalikh" (p. 110).
- (b) "This Taj-ud-din was in the service of Malik Karim-ud-din hamzah at Naghawr of Siwalikh." (p. 200).
- (c) "The seat of territory, Ajmir, with the whole of the Siwalikh (territory), such as Hansi, Sirsuti; and other tracts were subjugated." (pp. 468-469) .
- (d) A year subsequent to this. In 624 a.h. (A.D. 1227), he marched against the fort of Mandawar within the limits of the Siwalik territory (p. 11). (Raverty's translation of the Tabaqat-i-Nasiri.)
विजयेन्द्र कुमार माथुर ने लेख किया है ...उसिरगिरि (AS, p.104): उसिरगिरि पर्वत का उल्लेख दिव्यावदान पृ. 22 में है। उसिरगिरि का वर्तमान नाम सिवालिक पर्वतमाला है। उशीनर और उशीरगिरि या उसिरगिरि नामों में काफ़ी समानता है और इनकी स्थिति में भी साम्य है।
Delhi (Siwalik) pillar inscriptions of Visaladeva-Vigraharaja of A.D. 1114
James Tod (Annals of Haravati)  writes that In the first place, it is of no small moment to be enabled to adjust the date of Beesildeo, the most important name in the annals of the Chohans from Manik Rae to Pirthi Raj, and a slip from the genealogical tree will elucidate our remarks.
[p.417]: The name of Beesildeo (Visaladeva) heads the inscription on the celebrated column erected in the centre of Feroz Shah's palace at Delhi. This column, alluded to by Chund, as "telling the fame of "the Chohan," was " placed at Nigumbode," a place of pilgrimage on the Jumna, a few miles below Dehli, whence it must have been removed to its present singular position. *
The inscription commences and ends with the same date, viz,, 15th of the month Bysakh, S. 1220. If correctly copied, it can have no reference to Beesildeo, excepting as the ancestor of Prativa Chahmana tilaca Sacambhari bhulpati; or 'Pirthi Raj Chohan, the anointed of Sambhur, Lord of the earth' who ruled at Dehli in S. 1220, and was slain in S. 1249, retaining the ancient epithet of 'Lord of Sambhur,' one of the early seats of their power. brought away an inscription of this, the last Chohan emperor, from the ruins of his palace at Hasi or Hansi, dated S. 1224. See comments thereon, Transactions of the Royal Asiatic Society, Vol I, p. 133. The second stanza, however, tells us we must distrust the first of the two dates, and read 1120 (instead of 1220), when Visaladeva "exterminated the barbarians" from Aryaverta. The numerals 1 and 2, in Sanscrit, are easily mistaken. If, however, it is decidedly 1220, then the whole inscription belongs to Prativa Chahmana, between whom and Visala no less than six princes intervene, and the opening is merely to introduce Pirthi Raj's lineage, in which the sculptor has foisted in the date.
I feel inclined to assign the first stanza to Visaladeva (Beesildeo), and what follows to his descendant Pirthi Raj, who by a conceit may have availed himself of the anniversary of the victory of his ancestor, to record his own exploits. These exploits were precisely of the same nature, — successful war against the Islamite, in which
[p.418]: each drove him from Aryavevia; for even the Mooslem writers acknowledge that Shahbudin was often ignominiously defeated before be finally succeeded in making a conquest of northern India.
If, as I surmise, the first stanza belongs to Beesildeo, the date is S. 1120, or A.D. 1064, and this grand confederation described by the Chohan bard was assembled under his banner, preparatory to the very success, to commemorate which the inscription was recorded.
- Balokhra, J. M. (1999) The Wonderland of Himachal Pradesh. Revised and enlarged 4th edition. H.G. Publications, New Delhi.
- "Early Chauhan Dynasties" by Dasharatha Sharma, pp. 11-13
- See Indian Antiquary , 1912, p. 196; ASR, VI, Plat e. XXI
- Aitihasik Sthanavali by Vijayendra Kumar Mathur, p.104
- Annals and Antiquities of Rajasthan, Volume II, Higginbotham and Co. 1873. pp.416-418