Lion & Unicorn Standards

Gate posts @ Holyrood Palace against a lovely blue sky.

Hadn't seen these gate posts in detail before (!) and noted the link with James V and the unicorn story that is documented on the tapestries at Stirling Castle.

It was actually the fact there was two flags on the gate posts that caught my eye - the Saltire and St George's cross.
... so far I haven't managed to find out much about the history of that so any suggestions or links you can offer would be appreciated!