A strong resentment of what came to be regarded as foreign rule began to develop. In Ireland, Italy, Belgium, Greece, Poland, Hungary, and Norway local hostility to alien dynastic authority started to take the form of nationalist agitation. The first revolt in the Ottoman Empire to acquire a national character was the Serbian Revolution (1804–17), which was the culmination of Serbian renaissance which had begun in Habsburg territory, in Sremski Karlovci. The eight-year Greek War of Independence (1821–29) against Ottoman rule led to an independent Greek state, although with major political influence of the great powers. The Belgian Revolution (1830–31) led to the recognition of independence from the Netherlands in 1839. Over the next two decades nationalism developed a more powerful voice, spurred by nationalist writers championing the cause of self-determination. The Poles attempted twice to overthrow Russian rule in 1831 and 1863. In 1848, revolutions broke out across Europe, sparked by severe famine and economic crisis and mounting popular demand for political change. In Italy, Giuseppe Mazzini used the opportunity to encourage a war mission: "A people destined to achieve great things for the welfare of humanity must one day or other be constituted a nation".