Hi Julian
Your pic it's very nice so it is the horse and uniform.

It's the "gala uniform" of the "Guardia Civil Montada" . It's a security militarized corp that secure roads , small villages ,crops ,sea limits, borders,airports,coasts and a long etc.They are very well armed.

There are two more security corps in Spain : "Policía Nacional" and "Policia Local" .

Policía Nacional : They are a civil corp focused on crime in general , they patrol cities.They work together with judges.They are armed.

Policía Local : They are a civil corp and do follow the city mayor. There is one Local corp on each city.They are arme.

Both "Guardia Civil" and "Policía Nacional" have specialised and elite units.