<answer>Russia</answer> had previously obtained recognition from the Ottoman Empire of the Tsar's role as special guardian of the Orthodox Christians in Moldavia and Wallachia. Now <answer>Russia</answer> used the Sultan's failure to resolve the issue of the protection of the Christian sites in the Holy Land as a pretext for <answer>Russia</answer>n occupation of these Danubian provinces. Nicholas believed that the European powers, especially Austria, would not object strongly to the annexation of a few neighbouring Ottoman provinces, especially considering that <answer>Russia</answer> had assisted Austria's efforts in suppressing the Hungarian Revolution in 1849.
Who was given the special role of guardian over the Orthodox Christians in Moldavia and Wallachia?
Russia