I played conservatively until I could create extremely strong fleets. I ended up with fleets of Medium sized ships, each containing approximately 70-90 in Missile or Beam attack (can't remember which now) and strong defenses against whatever type the Dread Lords were using at the time.

I created two Troop transports and then circled around the Korath ships until I could get to the world I was supposed to take over. By that time in the game, both the Korath and I had Huge hulled ships (it was a VERY long game) and so I used a fleet of Large and Medium ships while my Dreadnought took out the Korath Dreadnoughts...that is plural.

It really is just a matter of luck I think, to be able to get through that mission. It is exceedingly hard just because of those Dread Lords. It took me an innumerable number of tries.

Good luck on it though,
GalenEvil

The DLs are supposed to be nigh on invincible. However, they don't get any better over time (apart from being able to crank out ships faster as they build more factories). If you can survive, then eventually you'll make up the difference.

You've got to learn to fight clever- DL dreadnoughts are effectively invincible in the early game, but with a full sized low level fleet, you should be able to take out the troop transports. Instead of waiting for the DLs in orbit around your planets, send out fleets to intercept the troop transports, while avoiding the Dreadnoughts.

Also, while you can't actually kill the Dreadnoughts due to the stupid 1HP rule, you can wear them down with enough attack focussed ships. The DLs will then remove them to give them time to repair.

If you do loose a planet, make sure that you have troop transports on hand to retake it immediately. If you're lucky, you'll steal some powerful DL weapons tech, which can really turn the tide in your favour. I wouldn't advise deliberately loosing planets though, as the DLs will start stealing your Logistics tech...

I just tried this mission again and I must really take my hats off for the AI.

In early game, both the korath and dread lords attacked my planets with missile weapsons (10+ missile dmg from korath & 400+ missle dmg from dread lords), with a few points of mass driver defenses. So I build my ships with beam weapons and point defenses to counter their missile weapons. In mid game to my horror, the dread lords maintained their huge (400+) missile weapons without much defenses but the korath switched to beam weapons (30-60dmg) and shield defenses (10-30pts) to counter my beam weapons and point defenses!!   

How do i counter with ships attacking me left right center with beam & missle weapons, & shield defenses???

Hi!
You may find this post: In Defense of Drengi useful.

BR, Iztok

The best way to beat up DL are Spies btw. they cant counter spies and wont built anymore ships if you place spies on every single factory.

Btw, I've been playing on tough difficulty.

If I load up my cargo ships with offensive weapons the korath would counter them, doesn't that mean I'll need to research 2 types of offensive weapons?

Yes! I got the planet. All I did was conquer as many planets as I could. In this way, the Korath could not develop their ships fast enough. I managed to overpower them militarily and once I had ships strong enough to take out the Dread Lords' defensive, I made a final push and got the planet!