The Allied protectorates were the star systems and sectors in the Cardassian Union that were occupied by the United Federation of Planets, the Romulan Star Empire and the Klingon Empire following the Dominion War. The Federation Alliance forces were usually in charge of patrolling the less inhabited areas of the Union, giving Akellen Macet more starships to protect Cardassia and other densely populated areas. It was planned for these areas to be returned to the Cardassians when they had the resources to control them again. (DS9 novels: Abyss, Warpath)
The Romulan protectorates included the Orias system and the Almatha sector. (DS9 novels: Abyss, Warpath)
Ingav was a Federation protectorate. (DS9 novel: Abyss)
The Romulans withdrew their forces from the protectorates when the Romulan Star Empire fractured. Starfleet and the Klingons would pull out their forces when the Borg invaded in 2381. (ST - Destiny novel: Mere Mortals)