A series of columns from Dragon that expanded the Mystara setting and included various additions to the Basic Dungeons & Dragons rules (additional monsters, character classes, magic items, and more). It was presented in the form of fiction followed by related rules, with maps of the new areas as well. The story was told as the log of the captain and other crew members of an Alphatian skyship that travelled across various unexplored parts of the world, its mission to explore Mystara and negotiate trade agreements on behalf of the Empress of Alphatia. This complemented the setting information found in the Gazetteer and Hollow World books, and formed a consistent campaign that could be adapted by GMs.
The series ran from issue 153 (Jan 1990) to issue 188 (Dec 1992), after which it was replaced by The Known World Grimoire. The Princess Ark columns were collected together, edited, new artwork created, and additional rules added, to form the boxed set Champions of Mystara: Heroes of the Princess Ark (1993).
Later, as part of the celebrations for Dragon's 30th anniversary, a new instalment of the adventures was published in issue 344 (Jun 2006). This consisted purely of additional story, with no further rules.