Bearer of the Sword of the Thousand Lakes is a title Lan Mandragoran claimed for himself just prior to ordering his army of twelve thousand to charge one hundred fifty thousand Shadowspawn at Tarwin's Gap.
Though no specific mention of a Sword of the Thousand Lakes is made in the histories, Malkier was described as "a kingdom necklaced by a thousand lakes." The same document also reports that prior to moving him out of the country, Lan was given the ancient sword of the Malkieri kings; a Power-wrought blade. It is likely then that the sword given to him as a babe in arms was that same Sword of a Thousand Lakes that he cites as he claims this title.
- TWORJTWOT, Chapter 28