Mythic introduced three new lawn trophies in version 1.90 on September 5, 2007:
Albion Aniversary Trophy
Hibernia Aniversary Trophy
Midgard Aniversary Trophy
The names were mispelled that way in the game for a long time.
The trophies are statues of rearing horses. The horses are marble and their armor is cloissoné (melted glass on metal). I suspect that the inspiration for this trophy may have been cloisonné fish, a kind of trinket which is extremely popular in China.
There are no mobs associated with these trophies. You get them simply by talking to the census overseer outside the king's throne room. Your character must be level 40 or higher, and the account must have been active for five years or more. The account doesn't need to have been continuously active, but rather the active periods must add up to at least five years. For example, if you played two years, then cancelled for two years, then played again for three years, you would qualify for the trophy.
For years the process for obtaining these trophies was badly bugged and the game often refused to give them to people who qualified. These problems may or may not be fixed now.
Mythic introduced these trophies as part of a package with another trophy, the 5 Year Crest, so people usually think they celebrate the game's fifth anniversary. But actually Mythic added these trophies to the game on September 5, 2007, about a month before the sixth anniversary. The names "5 Year Crest" and "Anniversary Trophy", taken together, are confusing. Apparently the name "5 Year Crest" was supposed to refer to the total number of years that the account had been active, not the game's anniversary.
Here's what Mythic said about these trophies in the patch notes for version 1.90:
Players who have accounts which have been active for 5 years are eligible to receive two new trophies as rewards to our veteran players.
Players should visit the Census Overseer, in their capital city, just outside the throne room, to find out if they are eligible.
Note: Your account does not need to be active for 5 years consecutively, but 5 years accumulatively to be eligible. Characters also must be at least level 40 to be eligible.