Brick wall 1.4m high - do I need piers?

[Halitosis]

Hi,
I'm planning a free-standing brick wall 1.4m high x 3m long single brick width. It'll actually only be 1.1m high on one side due to a raised patio. There wont be any gates or fences attached.
How deep & wide should the foundation be (its a well compacted gravel sub base previously been under a patio, and well sheltered among houses), and should the wall have piers (and if so how many?)
Many thanks

 

[KRB78]

Try posting this in the building section...you might get more replys. Goodluck.