Knight is the third out of 13 titles in the game. It gives you an advantage over the Esquire.
From the moment you are given the title, the amount of XP and EGO earned in the game is multiplied by a factor of 1.5. In other words, you start earning XP and rewards in EGO 50% faster.
Your Daily Tribute and Faction Tribute become 1.5 times as much.
You can become a Knight one of the following ways:
There is a risk If you have become a Knight by accumulating the stake and then your stake in EGO drops below 10,000,000.
You will be informed if at least one of the risk factors occurs. You will have 48 hours to meet the requirements. If you don't meet them you might become an Esquire, or a Yeoman, or even a Commoner. That depends on your EGO balance.
If you get the Noble Title of Knight as a reward for completing a special quest your title will be assigned to you for life.
If not, make sure your EGO balance is well above 10,000,000 Ego. This way you will significantly reduce the risk of losing it.