In all editions of D&D up to and including the Rules Cyclopedia (which came out two years after the introduction of AD&D 2nd Edition), characters of the fighter class who reach the 9th experience level gain the title of "Lord" (or "Lady" for female characters). This is true even for AD&D2 and the RC, which both dropped individual level titles; elves in the RC rules attain the title of "Lord Wizard" or "Lady Maga" at name level, while dwarves simply add the "Dwarven" modifier before the standard title. Since halflings in the RC are, like all non-Advanced editions from B/X onward, are limited to 8th level, they gain the title of "Sheriff" at this point.
Besides sounding cool - albeit not matching up with the class-specific titles of other roles, such as "Wizard" for magic-users or "Master Thief" for guess who - the attaining of the rank of Lord or Lady also has some interesting implications for the setting. If one assumes that the title and experience level are directly linked, then only the greatest fighting-men and -women in the land can become Lords and Ladies; likewise, anyone with such a title must be one hell of a fighter.
I've had an idea for applying this in my campaign. In a world where these particular noble titles are granted based on merit and deeds, rather than simple inheritance, conflicts between nobles might be resolved with single combat instead of sending armies to clash while their masters watch from afar. The ever-excluded-from-the-rules joust might be one such way of settling disputes.
Plus, if someone is able to take a true Lord or Lady hostage, they had better have a small army at their disposal... or be a particularly crafty Wizard, with a capital "W".