Nevertheless, Britain became increasingly worried about the situation in Turkey, and Prime Minister Aberdeen sent Lord Stratford de Redcliffe, a diplomat with vast experience in Turkey, as a special envoy to the Ottoman Empire to guard British interests. Russia protested the Turkish agreement with the French as a violation of the Treaty of Küçük Kaynarca of 1778, which ended the Russo-Turkish War (1768–1774). Under the treaty, the Russians had been granted the exclusive right to protect the Christian sites in the Holy Land. Accordingly, on 7 May 1853, the Russians sent Prince Alexander Sergeyevich Menshikov, one their premier statesmen, to negotiate a settlement of the issue. Prince Menshikov called the attention of the Turks to the fact that during the Russo-Turkish War, the Russians had occupied the Turkish-controlled provinces of Wallachia and Moldavia on the north bank of the Danube River, and he reminded them that pursuant to the Treaty of Küçük Kaynarca, the Russians had returned these "Danubian provinces" to Ottoman control in exchange for the right to protect the Christian sites in the Holy Land. Accordingly, the Turks reversed themselves and agreed with the Russians.