一八四五年法国政府根据德国反动政府的要求,把马克思驱逐出巴黎,马克思被迫移居比利时。不久,恩格斯也到了那里。一八四八年革命失败后,两位朋友不得不分手了,马克思住在伦敦,恩格斯住在曼彻斯特。但是,他们在思想上的交流并未因此而终止。二十年中,他们几乎每天通信,彼此交换对政治事件的意见和研究工作的成果。 In 1845, according to the request of the German reactionary government, the French government expelled Marx from Paris and Marx was forced to move to Belgium. Soon Engels arrived. After the failure of the revolution in 1848, two friends had to break up. Marx lived in London and Engels lived in Manchester. However, their ideological exchanges did not end accordingly. In the course of two decades they communicated almost daily, exchanging views on political events and the fruits of their research work.