From the timesonline.co.uk article:
The eminent historian Richard Overy, editor of The Times Complete History of the World, chooses the dates that he believes have most influenced humanity.
The historian’s choice
1 c.3500 BC Invention of the wheel and plough in Mesopotamia (present-day Iraq); invention of the sail in Egypt: three fundamental inventions for trade, agriculture and exploration.
2 c.3200 BC Invention of writing in Mesopotamia: the means to record and understand human history.
3 c.3000 BC Founding of the first cities in Sumeria (present-day Iraq): origin of modern social and administrative structures.
4 c.1600 BC Modern alphabet invented: the essential means of communication of complex concepts and culture.
5 c.1600 BC Beginning of Greek civilisation: essential to Western heritage and the root of mathematics, philosophy, political thinking and medicine.
6 753 BC Foundation of Rome: the Roman Empire is a pillar of the modern age, producing ideas on justice, law, engineering and warfare.
7 c.670 BC Invention of ironworking: metallurgy is the key to further technical, economic and military developments.
8 c.551 BC Birth of Confucius, the founder of one of the world’s major philosophical systems.
9 490 BC Battle of Marathon: the Greeks repel a Persian invasion, securing the survival of Greek culture and science.
10 486 BC Birth of Buddha, founder of one of the world’s major religions.
11 327 BC Empire of Alexander the Great reaches into India: the first example of a long-term and often violent interrelationship between Europe and Asia.
12 202 BC Hannibal is defeated by Rome: the victory is essential to secure the survival and expansion of Roman civilisation.
13 27 BC Founding of the Roman Empire: this is the start of the classic period of Roman domination in Europe and the Mediterranean.
14 c.5 BC Birth of Jesus Christ, founder of the many branches of Christianity. The exact date is disputed.
15 AD 105 First use of modern paper: this replaced stone, slate, papyrus and vellum as a cheap and convenient medium.
Read the article and the rest of the 50 here.