The friendship between Marx and Engels is a model of revolutionary friendship.
From 1842, when Marx and Engels first met, in the past 40 years, in the great struggle of leading the international production movement, they United and fought against * * *, and established sincere friendship. Because of the need of revolutionary struggle, they have lived in two places for nearly 20 years, but their relationship has not alienated, but has become closer and closer. They correspond almost every day, talking about various political events and scientific theoretical issues, and guiding proletarian revolutionary movements in various countries. Marx not only admired Engels' profound knowledge and noble personality, but also cared about Engels' health. Once, Engels was ill, and Marx always hung in his mind. In his letter to Engels, he said, "I care about your health, just like your own illness, maybe worse." In order to "preserve the best thinkers", Engels financially supported poor Marx, enabling him to concentrate on the study of revolutionary theory. Engels went to his father's company to engage in "ghost business" against his original intention. When the first volume of Das Kapital went to press, Marx wrote to Engels and said, "I can only thank you for this!" " Without the sacrifice you made for me, I would never have finished the great works of three books. I hug you with gratitude. "Although Engels made great sacrifices, he always believed that being able to fight side by side with Marx for 40 years was the greatest happiness in his life. This lofty revolutionary friendship between Marx and Engels, as Lenin praised, "surpassed all the most touching legends about the friendship of the ancients."