Tiny Beetle

M and I did battle with an overgrown and very woody, neglected Forsythia bush on the front of the house today.  We had no choice but to hack it down and will start again with the new growth at the bottom of the plant. We found a few of these pretty little beetles on the twigs, they were only about 1cm long, but so beautifully patterned and shiny. This one is on the cuff of my gardening glove which gives it some scale.
Does anyone know what they are?