Elements of the 7th fleet made up the forces massed at Wolf 359 to battle the Borg in 2367. Along with the 3rd and 5th Fleets, the 7th was severely decimated by that confrontation. (Decipher RPG module: Starfleet Operations Manual)
Three months into the war, the Seventh Fleet was employed to stop the Jem'Hadar in the Tyra system in 2374, and only 14 ships survived of the original 112 engaged there. (DS9 episode: "A Time to Stand", DS9 - The Dominion War novelization: Call to Arms...)
They again took heavy losses at Sybaron, and was still at half strength during the assault on the Tibor Nebula. Benjamin Sisko was on Earth when the Seventh Fleet was attacked by the Dominion. (DS9 episode: "The Reckoning", DS9 novel: Hollow Men)
In 2375, the 7th Fleet, including the USS Destiny, launched an assault on the Kalandra sector, based on intelligence from Elim Garak that the Cardassians forces were weak there. (DS9 episode: "Afterimage")
After the Dominion War, the this fleet was rebuilt and staffed with rugged survivors of numerous conflicts that had previously left the 7th in ruin. With a high standard of training, this is a prestigious post-war posting. (Decipher RPG module: Starfleet Operations Manual)
The RPG The Dominion War Sourcebook: The Fires of Armageddon, published by Last Unicorn Games after they had lost their Star Trek licence, states that the 7th fleet was under the command of Admiral Bellamy and included the USS Kymyr, USS Iberia, USS Shima'van and USS Tyler.