The best security for the unity and peace of the empire was the never-ceasing activity of Charles himself, who incessantly perambulated his realm from end to end so long as life was in him. It was his own frequent visits to Saxony, Italy, or Bavaria, that were the best means of keeping those outlying provinces in loyalty and obedience. But he had also a regular system of travelling commissioners who were always moving round the realm, and reporting to him on the needs and requirements of the different provinces. [Sidenote: The Missi Dominici.] The circuits of these _Missi Dominici_, or royal legates, as they were called, were fully settled by him only in 802, but he had been employing them less systematically at a far earlier date. His father and grandfather, Pippin the Short and Charles Martel, had been wont to send out occasionally travelling commissions (_Missi discurrentes_), but it was Charles the emperor who multiplied and systematised their activity. By his arrangements his emissaries, who were sometimes clerics, sometimes laymen, were appointed for a year’s duty over a certain number of countships. They visited the assemblies of the inhabitants of the district, summoned to the count’s _Mallus_,[52] and inquired into the state of the provinces. Complaints against the count himself or the local bishop were brought before them, and they would send them up to the king or take account of them on the spot. We sometimes find _Missi_ charged with other duties, such as the conduct of an embassy or a warlike expedition, but this terminal inspection of the local governors was their primary duty. As long as men of probity and strength were chosen, no better machinery for keeping together the wide empire of the Franks could have been devised. Footnote 52: See page 125.