 Complete the following phrase:  Novgorod signed a treaty with Casimir IV of Poland-Lithuania and invited him to rule as a prince. The treaty safeguarded the Orthodox church in Novgorod: the posadnik was to be Orthodox and the king was not allowed to build Catholic churches in the Novgorod Land. In spite of this, Ivan III launched his first campaign against Novgorod in 1471 alleging that they converted to Catholicism. After the Novgorodian army was defeated in the 