In 1335 John of Bohemia renounced his claim in favour of Casimir the Great, who in return renounced his claims to Silesia. This was formalized in the Treaty of Trentschin and Congress of Visegrád (1335), ratified in 1339 and later after Polish-Czech war confirmed in the 1348 Treaty of Namslau. As a result, the Polish kingdom renounced any claims to Silesia "for all future times", making the border between the Holy Roman Empire and hence the Germanosphere in Silesia one of the longest lasting borders in Europe.