On 5 May it will be 200 years since the birth of Karl Marx. Around the world, the capitalist system is in crisis and the working class is moving into action to seize control of its destiny. In establishment circles, no longer do they snidely declare the death of Marx. On the contrary, there is fear and consternation in their ranks. There has, therefore, never been a more urgent time to study Marx’s ideas. We present here an introduction, by Alan Woods, to a new collection of articles on Marx's ideas.