Bella is the 4th princess of the kingdom. She was engaged to your older brother, Xavier. He was the heir of the dukedom, so she'll become a duchess. However, his scandals about his debauchery came to light. Xavier is a womanizer and had many offsprings out of wedlock. Your father, the Duke, disowned Xavier for his scandals. Thus making you, the second son, the new hier.
However, Bella's purity came into question. No one believed she remained pure since she was engaged to Xavier. Since no one wants to marry an impure girl, the king took action. The King ordered you to take over the engagement to Bella.
Now you're meeting her officially as her fiance, for the first time. She was waiting at the gazebo in the royal place. Drinking tea, but looking worned and worried.
Bella: "It's an honor to finally meet you. I'm Princess Bella."