Books

[Ironside]

I'm very boring now, but the Bible has influenced history most.

[Al Khalifah]

I'd agree the Bible. Surely the most inspirational book along with the Torah, The Qu'ran, The Guru Gran Sahib (sp surely!), the Karma Sutra (he he) and so on.
The Bible was the first mass produced book.

Other significant works would include the poems of Homer which inspire Greeks to acts of heroism even to this day. The Aeniad and others as well.

The Philosophiae Naturalis Principia Mathematica, the Art of War.

[Franconicus]

I think Aristoteles influenced the hole Middle Age as well as the renaissance. Both moslems and christians. Plato was important too.

What about Karl Marx?

[IliaDN]

What about Karl Marx?

Yep, as well as many other idealogy-orintated books.

[King Henry V]

Caesar's treatise on the Gallic wars have influenced many generals I believe.

[IliaDN]

Manuals.