I would like to use the keyboard shortcut Alt+LeftArrow to go back a page in Safari. I tried adding this shortcut in System Preferences / Keyboard Shortcuts, but it had no effect. What can I do instead?
I am able to use System Preferences to assign other keyboard shortcuts to Safari's Back command. I am also able to assign Alt+LeftArrow to other menu commands in other apps. But Safari obstinately insists on interpreting Alt+LeftArrow as "scroll left a page", and it ignores my attempts to override that behaviour.