So this is how the quest chain for the Argent Tournament goes. I haven't finished it yet so it ain't finished, check back here regularly for updates.
The Chain starts with Crusader Rhydalla at the back of the tent at 70,23 (Icecrown).
The Black Knight of Westfall? - Go to Moonbrook in Westfall and investigate the house on the western edge of town called "Coopers Residence". This is the house nearest the Deadmines entrance.
There is a book on the floor called Dusty Journal. Open this and head back to Icecrown for the hand in.
Next up takes you to Crystalsong Forest for the quest The Seer's Crystal. Kill some Unbound Seers in the Forlorn Woods. A good place is 42,29.
Return and hand this in to get The Stories Dead Men Tell. Go and use the crystal at the graves at 79,23 and return to hand in.
There's Something About the Squire -Go to the area just Southwest of the round lake in the center of Crystal Song (38,59) and kill Skeletal Woodcutters until a Large Femur drops. Once you have it walk behind the neutral Maloric and "use" the Large Femur and then loot him. Pets? put them on passive. Return and hand in to get ...
The Black Knight's Orders. Use the enchanted girdle on the Black Knight's gryphon which can be found at his camp between the alliance tent and the graveyard at 77.7,21.6; it will take you to his home on an island off the north coast of Icecrown.
Make sure to pickup the daily quests first as you will be able to kill some scourge here. Walk up the hill, kill some scourge and get the "orders" and "invitation" from inside the hut.
Return to the quest giver and hand in. Now you have to reach the rank of Champion to get...
The Black Knight's Fall - Equip your lance and go get on the Stabled Argent Warhorse from the stable to the left of the flightmaster at 72.3,22.5 then go speak to Squire Cavin at 71.3, 23.1
He's on a box at the ring on the south west of the complex
Don't worry if it's night-time when you get this quest, you can still do it. Have a joust with him as normal. If he dismounts near the end DO NOT dismount yourself or he may evade/bug; wait for the game to dismount you, equip your normal dps gear and kill him.
Easy. Hand in and this opens up the daily group quest, Threat From Above (Ebon Hold) / (Argent Crusade) - I don't know what this means - I ripped it from Wowhead. It may mean the daily quest changes or it may mean Horde or Alliance quests. I may check later. I may not. Don't hold you're breath! Edit: Couldn't be arsed!
Anyway, when you hand in the Black Knight's Fall you get yourself yet another achievement...