Olga and Tatiana Romanov.
Around 1913.
Such a charming photograph.
Tsar Nicholas II riding with two of his daughters Olga and Tatiana. Both daughters can be seen in full military dress for their corresponding regiments that they are Colonel in Chief of.
This photograph may have been taken in August of 1913 as this when a parade occurred where both girls wore such dress and were accompanied by their father. If not it would have not been far out either way.

The busby and coat of a listed man of the 3rd Elizavetgradsky H.I.H. Grand Duchess Olga Nikolaevna’s Hussar Regiment. Named after Olga Romanov; a daughter of Tsar Nicholas II.
Olga held the rank of senior officer of the regiment; an honorary position. As did her sister Tatiana and her father of their own respective regiments.
This dates from the 1900-1914 I believe.