Despite many difficulties, he successfully surmounted all obstacles.

surmounted 是动词 surmount 的过去式。surmount 由前缀 sur-（表示"超过、在...之上"）和 mount（攀登、上升）组成，字面意思是"攀登到...之上"，引申为"克服、战胜"困难或障碍。