Newbie (pls be gentle!) - bird of prey question

Morning all.

I am fortunate enough to be able to walk straight up the South Downs from the house.  Late afternoon yesterday I took one of the kids and dog for a walk (and my camera kit to get photos of the new lambs).  At the top of the downs it felt like we started to be ‘tracked’ by a group of 3 or so of these birds.   Ive promised to find out for my daughter what they are. They were soaring to quite a height and then could travel fairly quickly laterally and down.  They are way, way bigger than a kestrel.  They look more eagle like but onbbioilsy wont be an eagle in Sussex. 

im guessing it will be fairly obvious to seasoned RSPB’ers!  Any help appreciated. apologies for low res photos - uploaded via my phone in the field