December 1795 Commodore Nelson under Earl St. Vincent:

After 15 years of being a post-capitan, Nelson hadn't fought in a great sea-battle of ships of the line and hadn't won a fight against an equal enemy. And so he was full of ambition and energy to take part in a battle or to fight against a really strong enemy to get honor for his name.
In 1795, Sir John Jervis became commander in chief of the Mediterranean fleet, and he promoted Nelson to commodore, with command of a small squadron and a flagship with his own flagcaptain. Nelson's order was to evacuate Corsica and Bastia. In those days the Spanish kingdom had changed sides and allied with the revolutionary French, who had just conquered Italy under the command of General Bonaparte. The Mediterranean Fleet left the Mediterranean Sea and started to blockade the Spanish Atlantic ports like Cadiz and others. During this mission, the main port for the English Mediterranean Fleet was Gibraltar.
Nelson had a good relationship to Sir John. That was why Nelson got the ship of the line "Captain" with 74 guns, under the command of Captain Ralph Miller, and he stayed commodore of the British Fleet.