regions and set up a transfer base for expeditionsto regions west of South Asia. All these tasks weresuccessfully completed after three voyages and Zheng Healso accumulated rich sailing experience. By that time，the reign of Emperor Yongle entered a golden age and thecountry became even stronger. Therefore， Emperor Yongleordered Zheng He to make a fourth expedition to reachthe unknown Muslim world west of South Asia.
The fourth voyage to the western oceans marked a newphase in Zheng He，s marine activities. He spent moretime conditioning and preparing than for the first three.
This time he was to visit countries and regions of the ArabWorld where people believed in Islam. To cope with thedaunting task of translation and interpreting， Zheng Hemade a special trip to Xi，an and invited Hasan， Imamof the Great Mosque of Yangshi， who knew Arabic， andinvited him to go along. Before setting out， Zheng Heasked for Emperor Yongle，s approval to build a TianfeiPalace in Changle， Fujian， for the worship of GoddessTianfei， or Mazu， who protected seafarers and fishermen.
In January， 1513， Zheng He started his fourth voyage，commanding a massive fleet. Following the old route，he arrived in Sumatra after passing Champa， Java，Palembang， Malacca， Pahang and Kelantan. Located in thenorthwest of Sumatra Island， with seas in the north andmountains in the south， the country of Sumatra served as
半岛的航路，在这一带地区树立明王朝的声威，同时也为向南亚以西地区远航建立中转基地。通过三次出使，郑和已圆满完成了上述任务，并积累了丰富的航海经验。此时，永乐朝进入了鼎盛时期，国力更加雄厚。为此，永乐皇帝命令郑和第四次出使西洋，向南亚以西未知的伊斯兰世界挺进。
第四次下西洋标志郑和航海活动进入了新阶段，所以出使前的休整及准备的时间较之前三次都长。这次计划访问的国家和地区属阿拉伯世界，人们都信奉伊斯兰教，翻译任务十分繁重。为此，郑和专程赶往陕西，求得通晓阿拉伯语的西安羊市大清真寺掌教哈三同行。远航前夕，他奏请永乐皇帝准予在福建长乐兴建天妃宫以祭祀海神天妃（妈祖），祈求保佑航海平安。
1513年1月，郑和率领庞大船队开始第四次出访，沿着旧路，经占城、爪哇、旧港、满剌加、彭亨、急兰丹等国到达苏门答剌。苏门答剌国位于今苏门答腊岛西北部，北临大海，南靠大山，为从南海通往印度洋的海上东西交通孔道。郑和船队在这里设有“官厂”（货物转运站），储存船队与各国贸易的货物以
a maritime transport channel linking the South China Seaand the Indian Ocean. There Zheng He，s fleet had a “stateplant” (cargo transfer station) which stored goods tradedbetween the fleet and the foreign countries， as well as allkinds of necessities for the fleet. This station was to play avery important role in Zheng He，s future foreign visits.
When Zheng He，s fleet arrived in Sumatra， the countrywas torn by civil strife. Under orders from EmperorYongle， Zheng He，s fleet interfered in the strife and putan end to it. The story goes like this. The former king ofSumatra was attacked by the king of Nakur， a country tothe west. The Sumatran king was killed by a poisonedarrow in the fight， and half of Sumatra，s land was takenover by Nakur. As the prince of Sumatra was too young toseek revenge for his father，s death， the queen of Sumatravowed in public that she would marry whoever couldavenge her husband， recover the lost land and managethe country. A fisherman answered her call， saying thathe could avenge the king，s death. With the army underhis command， the fisherman fought bravely against theenemy. He recovered the lost land and killed the king ofNakur. The queen， living up to her promise， married thefisherman and made him king of Sumatra. In 1409， thefisherman king dispatched an envoy and paid tribute tothe Ming Dynasty. Three years later， however， the princeof Sumatra grew up. He conspired with officials who were
及船队所需的各种备用物品。在郑和下一阶段的对外交往中，其地位显得十分重要。
郑和船队抵达苏门答剌时，正逢该国发生内乱。郑和奉永乐皇帝之命一举平定之，情况如下：苏门答剌前国王受西面那孤儿国的花面王攻击，在抗战时中毒箭而死，国土也被那孤儿国占去了一大半。这时王子锁丹罕难阿必镇尚幼，还不能为父报仇；苏门答剌王后则当众宣誓，能替我丈夫报仇、收复国土者，我愿以身相许，做他的妻子，和他共同管理国事。此时，有一个渔翁出来说道：我能替王后报仇。于是，渔翁率领军队勇敢作战，果然收复失地，杀死了花面王。王后不负前盟，做了渔翁的妻子。这个渔翁就成了苏门答剌的国王。1409年，渔翁王曾遣使向明朝进贡方物。三年后，先王子锁丹罕难阿必镇长大成人，与反对渔翁王的部将合谋，将其义父渔翁王杀死，夺取了王位。渔翁王的儿子苏干剌见此情状不得不率众逃入山中，自立为王并不断向先王之子发起攻击。1413年，锁丹罕难阿必镇又遣使向明朝求援，永乐皇帝答应了他的请求，于是命令郑和第四次下西洋时出兵相助。
against the fisherman king and killed his stepfather for thethrone. The son of the fisherman was forced to retreat intothe mountains. There， he made himself king and launchedcontinuous attacks on the son of the former king. In 1413，the son of the former king sent an envoy to the MingDynasty and asked for help. Emperor Yongle granted hisrequest and ordered Zheng He to give him a hand duringthe fourth voyage to the western oceans.
When Zheng He first arrived in Sumatra， he did notbother to interfere in the war. Instead， he presented hiscredentials to the king of Sumatra， bestowed gifts atcourt and conducted trade with the country as usual.The son of the fisherman king was annoyed by ZhengHe，s seemingly normal practices. Displeased that ZhengHe did not present him with any gifts， the fisherman，sson attacked Zheng He. Zheng He，s fleet fought backin self-defense and collaborated with the force of theSumatran king. After a fierce battle， the fisherman，s sonwas defeated and fled to Lambri. Zheng He，s army wasin hot pursuit and did not withdraw until the son and hiswife were captured alive. The two of them were sent backto China where Emperor Yongle ordered the Ministry ofJustice to put the son to death.
After the problem of Sumatra was brilliantly andcompletely settled， Zheng He divided his fleet into two，one part would head westward to explore routes along
郑和来到苏门答剌，没有急于动手，按惯例向国王递交国书，进行赏赐和贸易。对于郑和这些看来十分平常的举动，苏干剌却非常不满，恨郑和没有赏赐给他，于是带领部下数万人前来攻打郑和。郑和以自卫反击的方式，与国王锁丹罕难阿必镇的军队配合，与之展开激战。苏干剌战败逃亡南渤利国。郑和穷追不舍，直至将苏干剌及其妻子俘获方才收兵，将其押回中国，交由永乐皇帝圣裁。永乐皇帝命刑部将苏干剌处斩。
郑和在干净彻底解决苏干剌问题以后，分出船队向西探测赴非洲大陆东岸的航路，大部分船队则经锡兰、加异勒到达古里。在古里稍事休整，就向西横穿阿拉伯海，向对岸波斯湾的忽鲁谟斯驶去。
印度洋是世界四大洋之一，位处赤道，气候炎热且变化无常。有时晴空万里，波平如镜；有时乌云翻滚，恶浪如山。郑和船队在驶向忽鲁谟斯途中，就遭遇一次飓风的袭击。其时，汹涌的波涛像海妖水怪一
the east coast of Africa and the majority would head forCalicut through Ceylon and Jiayile. After a short break inCalicut， the fleet crossed the Arabian Sea in the west andheaded towards Hormuz on the other side of the PersianGulf.