Gundam Seed Destiny takes place after Gundam Seed.

 

It takes place in Cosmic Era 73. By now, the war that had taken place in Gundam Seed has been long ended and new characters are appearing taking the role of the nemesis. Athrun has left ZAFT and a new counterpart appears. His name is Shin Asuka, and he is one of the leading characters in the series. Athrun is now a part of Orb along with Cagalli.