In February 1854 the French and English Governments sent an ultimatum to Russia, requiring her to evacuate the Principalities, and in March they declared war against her. In June Austria followed suit, so far as demanding the evacuation of Moldo-Wallachia, and received permission from the Porte to drive the Russians out of the Principalities, and occupy them with her troops. She, however, contented herself during the continuance of the war with accumulating forces on her frontiers, and no doubt it was this threatening attitude which at length compelled Russia to evacuate them. Meanwhile active hostilities were proceeding between Omar Pasha and Gortschakoff. In the early part of 1854, the Russians having met with a reverse at Cetate, near Calafat, the Russian army was ordered to invade Turkey, and, having succeeded in crossing into the Dobrudscha at Galatz, Braila, and Ismail, it was deemed necessary to capture Silistria as a strategic post, in order to ensure the safety of the advancing army. In May 1854 the Russians attacked that fortress unsuccessfully, and after they had attempted to storm it four times, the Turks (in June) assumed the offensive, and made a sally, during which one of the Russian generals was slain. In the same month Nicholas, finding himself threatened by the Western allies in the Black Sea, and fearing to make an open enemy of Austria, whose forces were constantly increasing on her frontier, gave orders for raising the siege of Silistria, and subsequently for the entire withdrawal of his troops from the Principalities. This was not, however, effected until July, nor before the Russians had sustained another defeat from the Turks at Giurgevo. Then it was that the army was completely withdrawn, the Turkish vanguard entered Bucarest, and, says one of the historians of the war, 'the Wallachian nobles celebrated a Te Deum in the metropolitan church to commemorate the restoration of Turkish supremacy--the same boyards who, in 1829, kissed the hands of the Russians who had freed them from the Turkish yoke.' As for the hospodars. Stirbei of Wallachia, and Alexander Ghika of Moldavia, they had retired for safety to Vienna shortly after the outbreak of hostilities, and remained there until September, when the Austrians occupied the country with the approval of the Porte. They then returned for a short period, but Stirbei again abdicated permanently a month afterwards. The Roumanians wore compelled by the Russians to serve in their armies as long as they occupied the country, but a Turkish amnesty relieved them from the consequences of this procedure. The military operations of the contending Powers external to the Principalities have an interest for us only in their results. After the termination of the Crimean campaign, when Russia was compelled to sue for peace, the Treaty of Paris was concluded, and it contained stipulations of vital consequence to Moldo-Wallachia.