Offered by her owner to the riflemen of the First Brigade of the Polish Legions, she became the service mount of Commandant Józef Piłsudski, who entered Kielce on her in August 1914 and kept her as a riding horse until her untimely death 13 years later.
[2] She was an elegant mare of moderate height, about 14.3 hands (59 inches, 150 cm) at the withers, chestnut (light reddish-brown) in color, with markings that included a blaze and four white stockings.
Kasztanka was Józef Piłsudski's favorite horse and faithful companion in the Polish Legions' battles at the side of Austro-Hungary and Germany in World War I, for the independence of Poland.
Kasztanka was somewhat high-strung and hated artillery fire, but when her master asked, she remained controlled and obedient under difficult conditions, reciprocating his devotion.
[2] The Polish Legions' First Uhlan Regiment, commanded by Colonel Władysław Belina-Prażmowski, presented Piłsudski with new trappings for Kasztanka, and it was in these that she henceforth appeared.
In view of the worsening state of her health, veterinary assistance was summoned from Warsaw, and on the night of November 21–22 Lt. Col. Konrad Millak and Lt. Col. Władysław Kulczycki arrived.
They did not succeed in improving the state of [Kasztanka's] health, and at 10 o'clock that day they issued the following assessment: 'Grave internal trauma... severe distress to blood vessels and heart.'
"[2]The order of the day was signed by the 7th Uhlan Regiment's commander at the time, Lt. Col. Zygmunt Piasecki, who later complained that after Kasztanka's death Marshal Piłsudski would not talk to him.
The rest of her remains were buried in a park at the barracks of the 7th Uhlan Regiment, beneath a stone inscribed, "Here lies KASZTANKA, favorite combat mare of Marshal Piłsudski.