Answer: With the proudly repeated house words proclaiming "None greater than Grayson", few would argue against House Grayson being the proudest of the five great houses of the Compact of Arvum. With the sigil of a snarling griffin as a house sigil that all but dares foes into confrontations, most would imagine it was sheer strength of arms that has allowed House Grayson to lay claim to the vast majority of kings and queens of the Compact and to the longest unbroken dynasty of Arvum, but it is not so. Despite an almost innocent arrogance of many that swear fealty to Grayson, it is the political acumen of its leaders and the wisdom of its rulers that have given the house its position of prominence.
As legend has it, the very first king of the Compact during the time of the Reckoning was King Alar Grayson, who convinced the other great houses of Arvum to band together for mutual defense and founded the Compact so mankind might survive the hosts of demons marching upon the last bastions of men. It was he that called for us to make our stand at the city of Arx, and his family that further built us from five kingdoms into one powerful realm. And while there has certainly been wars between the great houses since the founding of the Compact and not always has the crown been in Grayson hands, it does seem we turn to the family in our darkest times.
Five hundred years ago was one such period. The Compact had been all but forgotten, splintering into five kingdoms once more, with the Graysons as but one among peers. That was the time when the Sylv'alfar, the so-called elves, thought they could exterminate us all where demons had failed. And it was then that Queen Alarice the Great renewed the Compact, once more united the houses, and smashed the Sylv'alfar for good and all.
So if the Graysons seem too proud of their house to outsiders, or too sure of their greatness, or too confident of their prowess, it is perhaps forgivable knowing their history. Not that it is easy to ignore tactless Graysons speaking of the Compact as their own, or often confusing what belongs to the Compact and what belongs to their House, or casually forgetting the brief periods of history where another great house laid claim to the crown, or forgetting that the other great houses are in fact their peers and not their subjects. Not easy, but perhaps understandable.