孫中山畢生革命，遭遇無數難關，其中經歷兩次幾以身殉大劫難，驚動一時：一為一八九六年十月遭清廷駐英國使館幽禁，蒙難於倫敦；二為民國十一年(1922)六月因部將陳炯明叛變，蒙難於廣州。幸得天助人助，終能化險為夷。尤為可貴的是，他並從危難中體悟出有益於革命發展的理則，革命事業不僅未因此受挫，反而更向前進展。其蒙難倫敦時，年方三十，值革命事業發展初期；廣州蒙難時，年五十七歲，已屆晚年，正當革命事業力求突破關頭。然其不畏艱險，奮勵無懈的志氣則始終如一。本文即欲藉由兩大蒙難事件，探究孫中山此種堅忍勇毅之拚鬥精神。
這兩椿近代中國革命史上駭人聽聞的事件，雖各在不同時空背景下發生，惟細心加以對照，還可以發現幾處共通點：
一是攸關孫中山性命：倫敦被難時，清廷不計代價，不論死活捉拿他；廣州蒙難時，叛軍暗夜圍攻總統府，也一樣不留給他活路。二是與三民主義有關的：倫敦被難有助於三民主義主張完成，廣州蒙難使三民主義著述浴火重生。三是與蔣中正有關的：倫敦被難故事啟發他奮然有革命之志，廣州赴難加深他與孫中山密切關係，有利於日後之繼起革命事業。四是與革命進展有關的：倫敦被難使孫先生聲名遠播，更加注重宣傳：廣州蒙難促使孫中山重整黨務，益覺革命軍之必要性，加速建立黃埔軍官學校，不僅兩廣革命基地賴以鞏固，且為北伐統一創造有利條件。
綜本文所述，「堅毅不屈，愈挫愈奮」，正是彰顯孫中山英雄本色之最好詮釋，倫敦被難時如此，廣州蒙難時亦如是。

Dr. Sun Yat-sen's revolutionary career contained numerous challenges. His being　kidnapped in London in October 1896 and besieged by Ch'en Chiung-ming in Canton　in June 1922 were the two incidents that shocked the world. Fortunately, he was not　only escaped with his life in the two incidents but also learned from the crises the　principles for his revolutionary movement. When Dr. Sun was kidnapped in London, he was 30 and just started his revolution movement. When he was besieged in Canton, he was 57 and tried to make a breakthrough in his revolution. In both cases Dr. Sun made a determined effort to surmount all obstacles. In this paper I will study Dr. Sun's determination and perseverance in the two incidents.
The two incidents have the following similarities, although they occurred in different years：
Firstly, they concerned Dr. Sun's life. In 1896 the Ch'lng court ordered the arrest of him regardless of his life or death. In 1922 the rebellious army of Ch'en Chiung-ming also did not care about his life when they besieged the Presidential Hall. Secondly, they concerned The Three Principles of the People. After Dr. Sun was released in London, he dedicated himself to the idea of The Three Principles of the People. After the rebellion of Ch'en Chiung-ming was pacified, Dr. Sun restarted his writing of the Three Principles of the People. Thirdly, they concerned Chiang Kai-shek. The incident of 1896 provided a stimulus to Chiang's revolutionary spirit. The incident of 1922 drew close relationship between Sun and Chiang and this, in turn, helped Chiang' greatly in his revolutionary career. Fourthly, they concerned the development of the revolutionary movement. The kidnapping helped Dr. Sun gain far-flung fame, so he laid more and more stress on propaganda. The rebellion in Canton resulted in Dr. Sun's reform of the party. Because he strongly thought that he needed a revolutionary army, he founded the Whampao Academy. The newly-established army not only guarded the revolutionary base in Kwangtung and Kwangsi but also helped carry out the Northern Expedition.
In sum, Dr. Sun Yat-sen had persevering and undefeatable characters, and they are　best described in his performance in 1896 and 1922.