Number of Dukes

[5freemen]

I know this isn't really history, but does anyone know how many living Dukes there are in the UK? Are all these titles hereditary? How many of them also have higher titles, like Prince Philip, Duke of Edinburgh?

[kempie]

http://en.wikipedia.org/wiki/Dukes_in_Britain

[reinganum]

All dukedoms are hereditary; life peers are always created Baron X of Y(place). Baron is the lowest order of peerage.