Islam began when man's career on earth began---more precisely at the time of man's creation and his descent. Allah created Adam and Eve and enjoined them to worship Him and live a life of obedience to the Divine Will.
The Islamic way of life can be revived and reconstructed again and again with the help of the Quran and the traditions if ever, God forbid, the freshness of its true spirit wanes. The world no longer requires any new Prophet to revive Islam to its pristine glory. It is enough to have among us the learned people who know the Quran and the traditions of the Prophet and who are able to apply their teachings to their own lives and stimulate others to adopt and apply them in their lives as well. This is how the stream of Islam will continue to flow, refreshing the eternal thirst of mankind.
Islamic History is made up of Prophets of Allah T'ala from Adam to Muhammad (peace be on them), the Sahabah, and the great religious leaders who took up the challenges of their times, revived and reconstructed the Islamic way of life based on the Quran and Sunnah.
Sahabah (The Companions) 46
The Companions of Prophet Muhammad (s.a.a.w.). May Allah T'ala be pleased with them.
Earlier Prophets 20
The Story of Adam (alaihe Salam, peace be on him), as given to mankind by God.