In 1688, Bielke was a "fændrik" in the Royal Life Guards. In 1690, he was a second lieutenant in a Guards Battalion in English service in Ireland. Later that same year he was promoted to first lieutenant and in 1691 to captain. In 1693–94, he served with the Royal danois and was wounded in the Battle of Neerwinden. In September he and Christian Gyldenløve returned to Denmark, where he was promoted to major and put in charge of a battalion in Oldenburg.