Kammala jumla mai zuwa: An haifi Kaulbars a Mödders a cikin Gwamnatin Estonia zuwa Baron Hermann Wilhelm von Kaulbars da Alexandrine Emilie kuma yana da ɗan'uwa, Nikolai Reinhold Friedrich. Alexander da Nikolai sun girma a Saint Petersburg kuma suna da bangaskiyar Lutheran. Ya fito ne daga Baltic Jamusanci mai daraja na asalin Pomeranian. Iyalin sun kasance masu daraja na Sweden. Dukansu mahaifinsa da ɗan'uwansa sun tashi zuwa matsayin janar a cikin Sojojin Rasha na Imperial. An koyar da shi a Makarantar Ruwa ta Nikolaev. Kwarewarsa ta farko a yaƙi ya kasance a cikin 1861, yayin da yake aiki tare da Egersky Guards Regiment a cikin dakile
Tashin hankali na Poland.