protection from direct assault at the price of corporate interference on the pettiest levels, but once a townsman left the city walls, he (for women scarcely travelled) was at the mercy of often violent and lawless nobles in the countryside. Because much of medieval Europe lacked central authority to provide protection, each city had to provide its own protection for citizens - both inside the city walls, and outside. Thus towns formed communes which were a legal basis for turning the cities into self-governing corporations. In most cases the development of communes was connected with that of the cities. However, there were rural communes, notably in France and England, that formed to protect the common interests of villagers. At their heart, communes were sworn allegiances of mutual defense. When a commune formed, all participating members gathered and swore an oath in a public ceremony, promising to defend each other in times of trouble, and to maintain the peace within the city proper. The commune movement started in the 10th century, with a few earlier ones like Forlì (possibly 889), and gained strength in the 11th century in northern Italy, which had the most urbanized population of Europe at the time. It then spread in the early 12th century to France, Germany, Spain and elsewhere. The English state was already very centralized, so the communal movement mainly manifested itself in parishes, craftsmen's and merchants' guilds and monasteries. State officialdom expanded in England and France from the 12th century onwards, while the Holy Roman Empire was ruled by communal coalitions of cities, knights, farmer republics, prince-bishops and the large domains of the imperial lords. In eastern Europe, the splintering of Kievan Rus' allowed the formation of veche communes like the Novgorod Republic (1136-1478) and the Pskov Republic (1348-1510). One in four urban communities in France were under the administration of mayors and (Northern France) or consuls and (Southern France) by 1300, and this number increased rapidly in the next 2 centuries due to the financial demands of city wall-building. Many were granted the rights to assembly, and executive power was often concentrated in one elected official, the mayor or first consul, with an advisory body of . Election was often restricted to the wealthy local merchant elite. In medieval Spain, urban communities were self-governing through their or open council of property-owners. The larger towns delegated authority to (town councillors) and (law officers),