Frederick was born as the son of Count Johann Georg I of Solms-Laubach (1547-1600) and his wife, Margarethe of Schönburg-Glauchau (1554–1606).

When his father's inheritance was divided in 1607, he received the districts of Rödelheim, Pletenheim and Assenheim.

On those days, officers were sometimes operating as a mercenary leader on behalf of princes or cities, or on their own account.

He is first mentioned as a participant in the Battle of Nieuwpoort on 2 July 1600 on the Dutch side under Maurice of Orange, who won here against the Spanish under Archduke Albert VII of Austria.

After Frederick III's death, he continued so support Sophie in the regency until her second son Albrecht came of age on 26 May 1639.