Rolan the Forgotten King

Rolan The Forgotten King is a 2010 manga by Takumi Yoshino.

During the Clauven Empire, seven-year-old Princess Étoile du Clauven was kidnapped by an assassin but was rescued by a guard--Rolan Flameberge. Ten years later, the world of Avalon is torn in conflict between two countries--the Clauven Empire and the Commercial City Union. With the Clauven Empire fighting a losing war, the Commericial City Union's leader, Commander Amenti, had a proposal to end the conflict: his marriage to Étoile. Étoile wants nothing to do with Amenti and pleads with Rolan to save her from her fate. Étoile's wedding day approaches, Rolan crashes the wedding and rescues her. As mysteries surround Amenti and the Union, Rolan and Étoile try to stop Amenti and the war.

This series provides the following tropes:

 * Always Save the Girl
 * Arranged Marriage: Between Amenti and Étoile.
 * Bare Your Midriff: Étoile.
 * Big Bad: Amenti.
 * Bodyguard Crush: Étoile.
 * The Champion: Rolan to Étoile.
 * Clingy Jealous Girl: Étoile gets quite peeved when she learns the guide that they're looking for is a girl.
 * Child Marriage Veto: Étoile does not want to marry Amenti.
 * Detached Sleeves: Étoile.
 * Elegant Gothic Lolita: Étoile wore this in flashbacks when she was a child.
 * I Will Protect Her
 * Meaningful Echo: Rolan's rescue of Étoile during her wedding mirrors his rescuing her from an assassin.
 * Parental Abandonment: Étoile's parents died when she was a child, leaving Étoile to be raised by her uncle. Rolan's parents were both soldiers and died during the war, leaving Rolan to be raised by his grandfather until he became a soldier.
 * Parental Substitute: Étoile's uncle and Rolan's grandfather.
 * Protectorate: Étoile to Rolan.
 * Rescue Romance
 * She Is All Grown Up: Étoile. Rolan obviously realizes this to some extent, but he tries to ignore the implications of it.
 * Ship Tease: Rolan and Étoile certainly have a heap of this.
 * Speak Now or Forever Hold Your Peace: Naturally, before Amenti and Étoile seal the deal for their wedding, Rolan comes to Étoile's rescue.