Complex sentence: On 8 February 1779, Gascoyne was commissioned and entered the British Army as an Officer with the rank of Ensign of the 20th Regiment of Foot, and in July of the following year, still as an Ensign, he joined the Coldstream Guards.
Split into simpler sentences: On 8 February 1779, Gascoyne was commissioned as a British Army Officer, joining the 20th Regiment of Foot with the rank of Ensign. In July of the following year, still as an Ensign, he transferred to the Coldstream Guards.