In 932 ME, Marthanda Varma had projected the construction of a line of fortifications on the northern frontier, but his death the following year prevented anything substantial being done. The experience gained in the course of the war with the Zamorin convinced the Dewan and the General, of the necessity of continuing and strengthening the lines which would not only protect Cochin in some measure from any possible aggression by the Zamorin, but would also be serviceable to Travancore in the event of an invasion from Mysore. The scheme was then taken up.