In the Lombard system, at the head of each _civitas_, as lord and as judge, was the _dux_, or duke. His title and his office being but the relic of his original high position of leadership in the army of the invasion, when his command was only subject to that of the king, the leader-in-chief of the army-nation and head of the military constitution, he held directly from the king, attended the royal _placita_ as the king's vassal, and held _placita_ of his own within his own jurisdiction, and over which he presided in person. Beyond the duties of his own particular jurisdiction his chief office was to assist the king by his presence and his counsel, when the king gave his judgments at the annual assembly in March, at the capital Ticinum. The importance of this concurrence of the _judices_ in all the king's decrees and official acts is illustrated by the fact that cases are rare in which this concurrence remains unmentioned. The usual practice is to introduce in the prologue which is commonly attached to the laws given out during each year of the king's reign, after the mention of the date "Kalendiis Martiarum," some such expression as "cum nostris Judicibus";[17] or "ad nos conjungerentur Judices";[18] or "per suggestionem Judicum";[19] to which is sometimes added the formula "omniumque consensum,"[19] or "cum reliquis nostris Langobardis fidelis." That legislation was not considered valid until such consent and advice was obtained, we can see from the prologue to the laws issued in the thirteenth year of the reign of Liutprand, in which he refers to certain important "causae" which had come under his jurisdiction, and for which additional legislation was necessary, the laws already existing failing to reach them. To meet the exigency new laws are enacted, but the king especially states that the cases must remain in abeyance until the new laws are confirmed by the _judices_ at the next assembly in March. In speaking of these "causae" in the above-mentioned prologue to the laws, he says: "Proinde providimus eas usque ad suprascriptum diem Kalendii Martiarum suspendere dum usque nostri ad nos conjungerentur judices," etc.[20] This attendance at the royal _placita_ represents the most important of the legislative duties of the _judex_ outside of his own jurisdiction.