Commander is a Navy rank. In the other services they would be known as the Lieutenant Colonels.
George Washington was Commander in Chief of the Continental Army.
https://www.loc.gov/rr/program//bib/ourdocs/commission.html#:~:text=Commander%20in%20Chief.&text=The%20Continental%20Congress%20commissioned%20George,could%20help%20unite%20the%20colonies.