I’ve heard it said that the Pennines (the hills in northern England) are named after the Apennines (the mountain range that runs through Italy). Is this true, or possible true, or a big pile of stinking nonsense?
But what about the Pennine Alps?
Pennine just means high.
In that case, I guess I should be asking a related question - how did the Pennines get their name?
True. The Appennini (double P) are the long range of mountains running through Italy from North to South. Have a look at this map.
The Pennines are a range of mountains in Northern England.
Plus there are the Pennine Alps (Italian: Alpi Pennine) mentioned by RM Mentock, which are a part of the Western Alps IIRC, but are different from the Appennini and from the Pennines.
Describing the Pennines as mountains is a bit generous.
I know that 
…but why were the English hills named this