After becoming the Prince Consort, the greatest benefit was the privilege he enjoyed while traveling.
It must be mentioned that even after decades of vigorous secularization movement, the retention of some Imperial privileges was the last bit of uniqueness remaining in the Imperial Family.
Initially, the ones who strongly requested the retention of some Imperial privileges were not the Imperial Family, nor the debate council representing the nobles, but the legislative council representing the commoner class.
If there were no privileges, what would distinguish the Imperial Family from commoners?
Legally, the Emperor was the Empire's highest Commander, while the Grand Secretary was merely the head of administration.
This also indicated that the main reason to maintain Imperial privileges was to constrain the Grand Secretary and to allow the legislative council, which held legislative power, to have more influence.
