ON: 3rd Yevsatgrad hussars formed 1784
2nd Turkish war 1787-91 Yekaterinslav army Prince Potemkin battles of Ochakov, Bendert, and Kilim
1792 poland battle of Ostrog
1794 Poland battles of Szczekocin,Maiejowice, praga
1805-07 battles of Austerliz, Monrugen, Wolsdorp and Eylau was under the command of Count von Buxhoeveden (most likely one of Isa baroness Sophia Von Buxoeveden relatives)
1812 Lubin , Borodino
1813-1814 campaign
1828-29 turkish war battles of Kulevchia and Adrianople
1831 Polish rebelion igane, Warsaw
1849 hungary battles of Samos and Tur
Crimea at the battle of Tchermaya there is one Order of battle that has the "Elisavetgrad Hussars" there which might be this unit but i doubt it.
On 11 July 1909 Olga N became the honorary colonel of this unit
WW I:
Aug 1914: 1st army
Sept 1914 Northern front reserve
Feb 1915 10th army 2nd battle of the Masurin lakes
Sep 1915 8th army Gillerschimdt cavalry corps
Oct 1915 3rd army IV Cavalry corps
Jun 1916 1st army I cavalry corps
Oct 1916 Danube Army reserve
Note: in the 1881-82 period all non-cossack regiment were converted to Dragoons this was not popular with alot of cavalry officers. Nicholas II brought back Hussars, lancers, ect