The Fall of Dom Ritter was ultimately caused by a Zombie Column from several nearby towns that was let into the walls by a Dom Verrater agent, name unknown. It marked the first and last use of zombies as an indiscriminate weapon against another city. Dom Verrater was punished through a series of taxes and fines.
See the Dom Ritter - Dom Verrater conflict
The Zombie Column is of uncertain origin, although most sources point to several towns which had succumbed upriver from Dom Ritter. Some historians suggest that these small outbreaks were caused by a hardened zombie falling into the Ritter River upstream, and were then aggravated by the Dom Verrater forces. Other historians point to local reports of increased Zombie activity.
Ultimately it comprised somewhere near 10,000 individual Zombies. The defenses of Dom Ritter were sufficient to stop this column normally, however after the Dom Verrater agent opened several gates and poisoned several wells the city of 60,000 fell quickly.
Defenses and Last Stand
Dom Ritter soldiers were mostly surprised by the attack, since it started in the quiet residential districts and spread quickly. By the time evidence of tampering was found, the column had grown to nearly 20,000.
Ultimately the last stand occurred in the market, somewhat tragically guarding a well that was already poisoned by the Dom Verrater agent. Here the last 3,000 soldiers of Dom Ritter tried to mount a defense using the reinforced buildings. Using the tunnels under the buildings, the last of the civilians fled.
Some citizens used the hidden tunnels underneath the city to escape outside; approximately 1,000 individuals escaped into the cold forest. Between zombies and the cold, only 100 stumbled into nearby towns.
As word spread out from the survivors that the attack had occured, it became clear very quickly what Dom Verrater had done. Most citizens of Dom Verrater were horrified by the attack, and demanded a response from their military command. When they denied, riots occured - in the aftermath, it became clear the city had ultimately caused the attack as records of correspondences with the unknown agent surfaced.
After this, Dom Lied organized the 1st Conclave of Doms. During this conclave sanctions and taxations were leveled against Dom Verrater, and several of the military commanders responsible were executed. The Conclave ultimately drafted and signed the 1st Liedian treaty to prevent subsequent attacks of this nature.
Dom Ritter became a hot bed of some 80,000 zombies; since then it has been untouchable, although it is estimated that only 20,000 zombies today are still in mobile condition.