Solution

Too late have I discovered how to anchor my sun umbrella so that it doesn’t fall over, pulling the base with it, whenever there is the hint of a breeze. Basically the iron base is too small a diameter for the weight of the shade when the wind hits it. With a hint from a neighbour I have added an old chimney pot to the equation and it appears to be working…… but it isn’t windy!
I wish I had known how to do it two weeks ago rather than today when the weather is about to break.

Having been able to sit outside of an afternoon for two weeks in sunshine and read has been like holidaying in foreign climes. I can’t remember what I do with myself ordinarily and it will be a horrible shock to the system to find out again.