Originally there was one posadnik, but gradually over time the office multiplied until, by the end of the Republic, there were something like 24 posadniks. There were also posadniks for each of the city's boroughs (called ends - "kontsy", singular "konets" in Russian). The multiplication of the office dates to the 1350s, when Posadnik Ontsifor Lukinich implemented a series of reforms. Retired posadniks took the title "old posadnik", or "старый посадник") and the current, serving posadnik was known as the "stepennyi" posadnik ("степенный посадник"). In accordance with the reform of 1416-1417, the number of posadniks was increased threefold and stepennyi posadniks were to be elected for a six-month period. In this manner, the various boyar clans could share power and one or another of them would neither monopolize power or be left out if they lost an election. It, however, diluted power in the boyarstvo. Some scholars have argued that the Archbishop of Novgorod became the head of the Republic and stood above the fray of partisan politics that raged among the boyardom, but the archbishops seem to have shared power with the boyardom and the collective leadership tried to rule by consensus. The dilution of boyar power may, however, have weakened Novgorod in the 15th century, thus explaining the series of defeats it suffered at Moscow's hands and the eventual fall of independent Novgorod.