It's a mullein, or verbascum if you prefer your plant names in Latin. There are several in the garden and we didn't plant any of them. This one is the tallest, at 286cm, or 9 feet 4½ inches if you prefer your measurements in Latin (modern English inch from Old English ynce from Latin uncia=twelfth part).
Somewhat ironically, given my recent experience, I discovered this morning that the oil extracted from mullein can be used as a remedy for earaches.