Due to an identification glitch (and with help from The Hinton Hunter) I am slightly embarrassed to announce that the figure I had previously thought was General Alten is in fact General Cooke. My apologies to both parties and their descendants for any distress caused.
Major General George Cooke commanded the Guards Division at Waterloo where he was wounded. I haven’t been able to find out much of interest about his career other than he served in Flanders during the early part of the Napoleonic Wars and later, as a Major General, commanded at Cadiz from 1811 to 1813. It doesn’t look like he served directly under Wellington except at Waterloo but if anyone knows anything more please feel free to leave a comment. Cooke rose to the rank of Lieutenant General and died in 1837 at the age of 69.
For the record then, this is BN256 General Cooke mounted on BNH11 General’s Horse. The casting is vintage Hinton Hunt and is currently waiting in the queue for a re-paint.