Niko I Dadiani, Prince of Megrelia

Nikoloz "Niko" Dadiani , or Nikolay Davidovich Dadian-Mingrelsky (; 4 January 1847 – 23 January 1903), was the last Prince of Mingrelia from 1853 to 1867. Of the House of Dadiani, one of the leading Georgian noble families, he succeeded on the death of his father, David Dadiani, but he never ruled in his own right; during his minority, the government was run by regency presided by his mother, Princess Ekaterina, and in 1857, Mingrelia was placed under a provisional Russian administration. In 1867, Dadiani formally abdicated the throne and Mingrelia was directly incorporated into the Russian Empire. Dadiani mostly lived in Saint Petersburg, being close to the court. He was an officer in the Imperial Russian Army, distinguished himself in the Russo-Turkish War (1877–1878), and retired with the rank of major-general.

Early life Niko Dadiani was born in Zugdidi, Mingrelia's capital, in 1847. Niko was six years old in August 1853 when his father died, and he became Prince of Mingrelia as an autonomous subject of the Russian Empire. With the approval of Tsar Nicholas I, Niko was placed under the regency of his mother, Princess Ekaterina; the Russian bureaucrat Kornely Borozdin was assigned to him as a tutor. The regency council also included Niko's paternal uncles, Grigol and Konstantin.

The Dadiani family's luxurious life in Zugdidi was interrupted by the Crimean War, during the course of which, in 1854, the Ottoman troops advanced into Mingrelia. The Russian forces temporarily withdrew from the principality; Princess Ekaterina and Prince Niko took refuge in the mountains of Lechkhumi, at the monastery of Tsageri. After the war, in 1856, the mother and the son repaired to Moscow to attend the coronation of Tsar Alexander II and then followed the imperial family to St. Petersburg. On this occasion, Niko—enlisted at his birth as a cornet in the Life Guards Cossack regiment—was made aide-de-camp to the Tsar and commissioned as a poruchik in the Life Guards Caucasian Squadron of His Imperial Majesty's Personal Escort.

Niko Dadiani was then sent for further education in Paris. On his return, Niko, persuaded to accept a fait accompli, renounced his hereditary title of Prince Regnant of Mingrelia on 4 January 1867. With this, Mingrelia was formally annexed directly into the Russian Empire; Dadiani retained his palaces in Zugdidi and Gordi as his personal property. On his abdication, Niko was recompensed with the title of prince (knyaz), one million roubles, and a major's commission. His mother, brother, and sister were granted a lifetime pension. On 34 August 1874, he received the style and surname of Prince Dadian-Mingrelsky ("Dadiani of Mingrelia"). Princess Ekaterina (27 March 1875 – 10 December 1875); Prince Nikolay (30 December 1876 – March 1919), Gentleman of the Imperial Bedchamber; he died in a Bolshevik prison hospital at St. Petersburg without issue; His body was released to his fiancée, Princess Elena Eristavi, who buried him in the garden of a Georgian church in Russia. Princess Salomea (1 December 1878 – 3 December 1961), Lady-in-waiting of the Imperial Court of Russia; she was married to Major-General Prince Aleksandr Nikolayevich Obolensky (1872–1924) and died as an emigrée at Asnières-sur-Seine, France.

Niko Dadiani also had an extramarital daughter, Menik (1880–1954), with his distant relative Princess Kesaria Chikovani.