It's Ceanothus - there are several varieties. Some flower in autumn, some flower with more lilacy larger flowers, some are evergreen, some are not, some become tree like, others remain as wide spreading, fairly low shrubs.

Cheers Bamboo.

I have a friend who saw these shrubs on a hillside in California. He reckoned that there were more shades of blue through pink to white than he had ever seen in Britain.