Pedunculate Oak (Quercus robor) 
In winter we do not have a lot to go on, leaves are often the best indicator of tree species but the silhouette of trees without leaves does vary and this rounded appearance with a solid trunk and major branches is indicative of the English Oak.
It is also one of our most common trees so they are not hard to find and large trees of this nature are only going to be one of a handful of species anyway.
There are three other oak trees, the Sessile which I will talk about in the other photos, the Holm and the Turkey. The latter two are very different and cannot really be confused with the good old English Oak, they have acorns but the tree itself is quite different.
[continued on picture 2]