White lilac

We had two lilacs in the garden when we move in, one on each side. My mother-in-law very diligently pruned them after they had flowered, and the following year one of them just didn't start to grow again in the spring - don't know what happened to it but it didn't survive the winter. As it happens the builders would have had to dig it up anyway, but it didn't last that long...! Today's back blip is the one that did survive and is on the other side facing the opposite direction. We had an ancient lilac in England, and like this one it wasn't lilac coloured but white.