Sternus vulgaris and sternus unicolor
The upper bird is the Spotless Starling and is an adult, the lower one is a young Starling, sometimes referred to as European or Common Starling. The adults of both types show a purple and greenish sheen in good light.
The Spotless Starling is resident here all year round while the Starling is a winter visitor. They appeared today so winter must be approaching. The news showed snow in Northern Spain today.