Here's a bit of History: Shields.
Feel free to add or correct any information, or link any new entry to this post. There are two sections: The first one is by chronological order; the second one, by alphabetical order.
Thanks to Suikoman444 for this ant work!
Chronological order:
November 24, 2002
Frogzard Shield
June 24, 2003
Glave Shield.
August 26, 2003
Drakel Power Shield.
September 30, 2003
Grand Tower Shield.
October 28, 2003
Pumpkin Shield.
December 30, 2003
Mogloo, Farzhad Mogloo.
April 29, 2004
Chameleon.
June 15, 2004
Dreamcatcher.
June 17, 2004
Cheese, Corn, Wheat.
August 16, 2004
Shifter
August 24, 2004
Golden.
November 14, 2004
Nighthunter.
December 1, 2004
Gift Box (2004)
January 1, 2005
Dimensional.
January 20, 2005
Dragonslayer Shield
February 14, 2005
Hero's Heart
March 5, 2005
Undead Terror
June 24, 2005
Assassin Shield
July 1, 2005
Nemesis Shield
July 22, 2005
Shield of Rennd
November 4, 2005
Spellbreaker, Siege Tower Shield, Sackleberry Special
November 25, 2005
Gift Box (2005)
December 31, 2005
Frostval Wreath
February 25, 2006
Bone Shield
March 19, 2006
Four-Leaf Clover
April 13, 2006
Eggshell Shield
May 15, 2006
Paladin Shield
June 1, 2006
TropoShield, Ultimus
June 19, 2006
Father Time
August 10, 2006
Aerodu Shield
August 31, 2006
Reign Defender, Heir's Defender, Scion's Defender, Shadowbones, Umbralbones, Penumbral Bones
November 6th, 2006
Seashell
Janurary 1st, 2007
Winter Shield
February 2, 2007
Asgir Shield
March 18, 2007
Clover Shield, Mega Clover Shield
July 19, 2007
Flame Ruby Shield, Metalcutter Shield, Warsmith Shield
August 9, 2007
IronBreaker
August 19, 2007
Elven Barrier
September 27, 2007
Vampiercer, Golden Shield
October 4, 2007
Chaos/Unity Shield
Alphabetical order:
Aerodu Shield: August 10, 2006
Asgir Shield: February 2, 2007
Assassin Shield: June 24, 2006
Bone Shield: February 25, 2006
Chameleon: Shield April 29, 2004
Cheese: June 17, 2004
Clover Shield: March 18, 2007
Corn: June 17, 2004
Dimensional: January 1, 2005
Dragonslayer Shield: Janaury 20, 2005
Drakel Power Shield: August 29, 2003
Dreamcatcher: June 15, 2004
Elven Barrier: August 19, 2007
Eggshell Shield: April 13, 2006
Farzhad Mogloo: December 30, 2003
Father Time: June 19, 2006
Flame Ruby Shield: July 19, 2007
Four-Leaf Clover: March 19, 2006
Frostval Wreath: December 31, 2005
Gift Box (2004) December 1, 2004
Gift Box (2005): November 25, 2005
Glave Shield: June 24, 2003
Golden: August 24, 2004
Grand Tower Shield: September 30, 2003
Heir's Defender: August 31, 2006
Hero’s Heart: February 14, 2005
Mega Clover Shield: March 18, 2007
Metalcutter Shield: July 19, 2007
Mogloo: December 30, 2003
Nemesis Shield: July 1, 2005
Nighthunter: November 15, 2004
Paladin Shield: May 15, 2006
Penumbral Bones: August 31, 2006
Pumpkin shield: October 28, 2003
Reign Defender: August 31, 2006
Sackleberry Special: November 4, 2005
Scion's Defender: August 31, 2006
Seashell: November 6th, 2006
Shadowbones: August 31, 2006
Shield of Rennd: July 22, 2005
Shifter: August 16, 2004
Siege Tower Shield: November 5, 2005
Spellbreaker: November 5, 2005
TropoShield: June 1, 2006
Ultimus: June 1, 2006
Umbralbones: August 31, 2006
Undead Terror: March 5, 2005
Warsmith Shield: July 19, 2007
Wheat: June 17, 2004
Winter Shield: Janurary 1, 2007