Design Suitable Base for Known Force on a Post

BertSmurf

I am attempting to design a base to support a post that will be pulled horizontally at its top.
A 2D image of the post will be a simple inverted "T"
The top of the post will be pulled horizontally by a force of approximatly 900N
What I need to do is design a suitable base for this post that will prevent it from toppling (suitable weight and dimension)
I am a little confused on the mathematics that govern the force required to topple something like this.
A moment balance about the point around which the post will topple (the edge of the base) seems to imply that the problem is independent of the COG (since the prependicular distance wont change as COG is in the middle) and this cant be right.
Can some one please shed some light on this?

tiny-tim

Duplicate to this thread