Must one be a squire in order to be a knight?

I've had several people tell me that in order to become a knight in An Tir you have to first be a squire. I've also had some people tell me that is not true. There have been knights and squires on both sides of this so far from what I've heard in casual conversations. If you are a knight in An Tir, do you consider this to be the case? Why? If you are a squire in An Tir, do you consider this to be the case, and why? For those not in An Tir, is being a squire considered to be a necessity in order to become a knight in your kingdom? Are there any examples of knights made in recent years who have not first been squired? Also, if you are from another kingdom, is being a protege or apprentice considered essential before becoming a peer in your kingdom?