As a second son, Henry XXXV was, under the terms of an inheritance and succession treaty closed in 1713, not entitled to a share of Schwarzburg-Sondershausen, but only to a small apanage).

When he received Schwarzburg-Keula, he was upset with his family, including his siblings, and left the principality.

He settled on a country estate in Bürgel and maintained good contacts with his uncle, Duke William Ernest of Saxe-Weimar.

His elder half-brother Günther XLIII died childless in 1740, and Henry XXXV succeeded him as the ruling Prince.

He died unmarried in 1758, and was succeeded by Christian Günther III, the eldest son of his younger brother August I.