On December 18 1796, the East India Company Commissioners issued a proclaimation against the Pychy [Pazhassi]Raja. This led the Raja to seek aid from his former enemy Tippoo Sultan.
Tippoo agreed to supply the Raja with ammunition and to station 6,000 of his soldiers in the Wynaad.
Colonel Dow was given command of the EIC troops tasked with defeating the Raja. His men commenced the arduous climb up the Ghats towards the upland plateau that forms the Wynaad.
The Periya Pass.  As can be seen from the photo below this pass with its wooded slopes, and twisting nature was an ideal place for an ambush. The pass comes down the centre of the photograph, before turning towards the bottom left hand edge of the photo.
Colonel Dow's force marched up to the Wayanad via the Tammarasseri Pass from Calicut, and then travelled across the Wynaad heading north along the line of the peaks, on top of the plateau until the force reached the head of the Periya Pass with no opposition. They were in place by the 9th of March. A second party under Lieutenant Mealey was less successful. Comprised of two companies of Sepoys, it climbed the Karkur Pass. Over three days, the 9th, 10th and 11th of March this detached had to fight its way opposed by "some thousands" of Nairs and Kuchiars. It had to retreat via the Ellacherrum Pass. One subadar, 2havildars, 2 naigues, 1 waterman and 32 sepoys were killed or missing, and 67 more wounded, including Lieutenant Millinchamp. About half the force had become casualties.
Colonel Dow had left the coastal plain with inadequate supplies, and though his forces lack of control of the passes, he was unable to get further supplies. By the time he reached the head of the Periya Pass he had only five days rations left.
Major Anderson who was expected to bring further supplies up from Cannanore and Tellicherry, found that his Mappillas guides refused to turn up. Six armed messengers arrived from Tippoo Sultan who remonstrated with Colonel Dow for his marching through the Wynaad.
At this point Colonel Dow decided to leave the force and to return to the coast. Major Cameron was left in command of the troops left at the summit of the pass.
It would appear that Major Cameron was killed on the 18th of March 1797 whilst fighting his way down the Periah Pass.
Poor Helen Cameron was already a widow by the age of 18.
 Periah village and pass is nowadays known as Periya. 11O 50’ 11.36” N 75O 50’ 08.20” E. The village is 24 miles due east of Thalassery, and 31 miles due east of Kannur The area at the top of the pass is 740 metres above sea level.
William Logan’s “Malabar Manual” in two volumes.Originally published in 1887. This entry and the others in this book are taken from the 2000 edition edited by Dr. P.J. Cherian, and published by the Kerala Gazetteers Department.Volume 1, pages 517 & 518.