The men of my family, we are taught to place the needs of others before those of our own. I will see that you are kept from harm. It is my duty to House Solidor.Larsa to Penelo, Final Fantasy XII
A noble Archadian family having a permanent seat on the Senate, and de facto control over the Ministry of Law. In the days following Archadia's establishment as an empire, House Solidor found itself in the opposition to the then-powerful military. Having won the ensuing struggle, it then initiated far-reaching revisions to the law in an attempt to prevent any further challenge to its supremacy. Subsequently, the Ministry of Law was created to monitor the military, with the order of Judges at its head. House Solidor's firm grip on the workings of the Empire can be felt to this day, with Emperor Gramis the fourth in a succession of Solidor emperors.House Solidor, Sage Knowledge
The members of House Solidor are Gramis Gana Solidor, the current emperor of Archadia, Vayne Carudas Solidor, the emperor's son and the consul of Royal City of Rabanastre, and Larsa Ferrinas Solidor, the emperor's youngest son. Vayne had two elder brothers whom he killed as per Gramis's orders.
The Archadian Judges serve House Solidor, though some are more loyal than others. Gramis takes the newest Judge, Gabranth, as his personal eyes and ears to report on Vayne and Larsa's doings, but Vayne becomes aware of this. Vayne stages Gramis's murder blaming it on the head of the senate, Chairman Gregoroth. He dissolves the Imperial Senate and becomes the sole ruler of the empire. Vayne tests Gabranth's loyalty after the emperor's murder and Gabranth ends up serving Larsa as his lord.
Princess Ashe and her friends kill Vayne during the battle above Rabanastre and Larsa assumes the throne. The dying Judge Gabranth asks his brother to look after Larsa, since without him House Solidor would disappear, resulting in the empire succumbing into civil war.
"Solidor" may have different origins: the word resembles the Italian "soli d'or" that means "golden suns". It may have derived from "solid" with the meaning "strong" too.