Ahmed I (Ottoman Turkish: احمد اول Aḥmed-i evvel; Turkish: I. Ahmed; April 18, 1590 – November 22, 1617) was the Sultan of the Ottoman Empire from 1603 until his death in 1617. Ahmed's reign is noteworthy for marking the end of the Ottoman tradition of royal fratricide; henceforth Ottoman rulers would no longer execute their brothers upon accession to the throne. He is also well known for his construction of the Blue Mosque, one of the most famous mosques in Turkey.
Ahmed was the son of Mehmed III and Handan Sultan, a Greek slave. When he ascended the throne, his aunts Ayşe Sultan, Fatma Sultan, Mihrimah Sultan, Fahriye Sultan, Mihriban Sultan, and Rukiye Sultan as well as his powerful grandmother Safiye Sultan were still alive. He had two siblings, Mustafa I and a daughter of Mehmed III which was married to Kara Davud Pasha.
Ahmed came to the throne in 1603 at the age of thirteen. In contrast to previous enthronements, Ahmed did not order the execution of his brother Mustafa, thus the Ottoman tradition of royal fratricide was brought to an end. This was most likely due to Ahmed's young age - he had not yet demonstrated his ability to sire children, and Mustafa was then the only other candidate for the Ottoman throne. His brother's execution would have endangered the dynasty, and thus he was spared.
In the earlier part of his reign Ahmed I showed decision and vigor, which were belied by his subsequent conduct. The wars which attended his accession both in Hungary and in Persia terminated unfavourably for the empire, and its prestige received its first check in the Treaty of Zsitvatorok, signed in 1606, whereby the annual tribute paid by Austria was abolished. Following the crushing defeat in the Ottoman–Safavid War (1603–18) against the neighbouring rivalling Safavid Empire led by Shah Abbas the Great, Georgia, Azerbaijan and other vast territories in the Caucasus were ceded back to Persia per the Treaty of Nasuh Pasha in 1612, territories which had earlier been temporarily conquered per the outcoming result of the Ottoman–Safavid War (1578–90). The new borders were drawn per exactly the same line as confirmed in the Peace of Amasya of 1555.
Ottoman-Safavid War: 1604-06
Upon ascending the throne, Ahmed I appointed Cigalazade Yusuf Sinan Pasha as the commander of the eastern army. The army marched from Constantinople on 15 June 1604, which was too late, and by the time it had arrived on the eastern front on 8 November 1604, the Safavid army had captured Yerevan and entered the Kars Eyalet, and could only be stopped in Akhaltsikhe. Despite the conditions being favourable, Sinan Pasha decided to stay for the winter in Van, but then marched to Erzurum to stop an incoming Safavid attack. This caused unrest within the army and the year was practically wasted for the Ottomans.
In 1605, Sinan Pasha marched to take Tabriz , but the army was undermined by Kose Sefer Pasha , the Beylerbeyis Erzurum of, marching independently from Sinan Pasha and consequently being captured as a POW by the Safavids. The Ottoman army was routed Urmia and had to flee to Van and the firstly with which to Diyarbekir . Here, Sinan Pasha Sparked a rebellion by executing the Beylerbeyis of Aleppo , Canbulatoğl Hussein Pasha , who had come to the help provice, upon the pretext that he had arrived too late. He soon died himself and the Safavid army was able to capture Ganja , Shirvan and Shamakhi in Azerbaijan. 
War with the Habsburgs: 1604-06
Grand Vizier Malkoç Ali Pasha marched to the western front from Constantinople on 3 June 1604 and arrived in Belgrade, but died there, so Lala Mehmed Pasha was appointed as the Grand Vizier and the commander of the western army. Under Mehmed Pasha, the western army recaptured Pest and Vác, but failed to capture Esztergom as the siege was lifted due to unfavourable weather and the objections of the soldiers. Meanwhile, the King of Transylvania, Stephen Bocskay, who struggled for the region's independence and had formerly supported the Habsburgs, sent a messenger to the Porte asking for help. Upon the promise of help, his forces also joined the Ottoman forces in Belgrade. With this help, the Ottoman army besieged Esztergom and captured it on 4 November 1605. Bocskai, with Ottoman help, captured Nové Zámky (Uyvar) and forces under Tiryaki Hasan Pasha took Veszprém and Polata. Sarhoş İbrahim Pasha, the Beylerbey of Nagykanizsa (Kanije), attacked the Austrian region of Istria.
However, with Jelali revolts in Anatolia more dangerous than ever and a defeat in the eastern front, Mehmed Pasha was called to Constantinople. Mehmed Pasha suddenly died there, whilst preparing to leave for the east. Kuyucu Murad Pasha then negotiated the Peace of Zsitvatorok, which abolished the tribute of 30,000 ducats paid by Austria and addressed the Habsburg emperor as the equal of the Ottoman sultan. The Jelali revolts were a strong factor in the Ottomans' acceptance of the terms. This signaled the end of Ottoman growth in Europe.
The resentment against the war with the Habsburgs and heavy taxation combined with a weakness of Ottoman military response to make the reign of Ahmed I the zenith of Jelali revolts. Tavil Ahmed launched a revolt soon after the coronation of Ahmed I and defeated Nasuh Pasha and the Beylerbey of Anatolia, Kecdehan Ali Pasha. In 1605, Tavil Ahmed was offered the position of the Beylerbey of Shahrizor to stop his rebellion, but soon afterwards, he went on to capture Harput. His son, Mehmed, obtained the governorship of Baghdad with a fake firman and defeated the forces of Nasuh Pasha sent to defeat him.
Meanwhile, Canbulatoğlu Ali Pasha united his forces with the Druze Sheikh Ma'noğlu Fahreddin to defeat the Amir of Tripoli Seyfoğlu Yusuf. He went on to take control of the Adana area, forming an army and issuing coins. His forces routed the army of the newly appointed Beylerbey of Aleppo, Hüseyin Pasha. Grand Vizier Boşnak Dervish Mehmed Pasha was executed for the weakness he showed against the Jelalis and replaced by Kuyucu Murad Pasha, who marched to Syria with his forces to defeat the 30,000-strong rebel army with great difficulty, albeit with a decisive result, on 24 October 1607. Meanwhile, he pretended to forgive the rebels in Anatolia and appointed the rebel Kalenderoğlu, who was active in Manisa and Bursa as the sanjakbey of Ankara. Baghdad was recaptured in 1607 as well. Canbulatoğlu Ali Pasha fled to Constantinople and asked for forgiveness from Ahmed I, who appointed him to Timişoara and later Belgrade, but then executed him due to his misrule there. Meanwhile, Kalenderoğlu was not allowed in the city by the people of Ankara and rebelled again, only to be crushed by Murad Pasha's forces. Kalenderoğlu ended up fleeing to Persia. Murad Pasha then suppressed some smaller revolts in Central Anatolia and suppressed other Jelali chiefs by inviting them to join the army.
Due to the widespread violence of the Jelali revolts, a great number of people had fled their villages and a lot of villages were destroyed. Some military chiefs had claimed these abandoned villages as their property. This deprived the Porte of tax income and on 30 September 1609, Ahmed I issued a letter guaranteeing the rights of the villagers. He then worked on the resettlement of abandoned villages.
Ottoman-Safavid War: Peace and continuation
The new Grand Vizier, Nasuh Pasha, did not want to fight with the Safavids. The Safavid Shah also sent a letter saying that he was willing to sign a peace, with which he would have to send 200 loads of silk every year to Constantinople. On 20 November 1612, the Treaty of Nasuh Pasha signed, which ceded all the lands the Ottoman Empire had gained in the war of 1578–90 back to Persia and returned to the 1555 boundaries.
However, the peace ended in 1615 when the Shah did not send the 200 loads of silk. On 22 May 1615, Grand Vizier Öküz Mehmed Pasha was assigned to organize an attack on Persia. Mehmed Pasha delayed the attack till the next year, until when the Safavids made their preparations and attacked Ganja. In April 1616, Mehmed Pasha left Aleppo with a large army and marched to Yerevan, where he failed to take the city and withdrew to Erzurum. He was removed from his post and replaced by Damat Halil Pasha. Halil Pasha went for the winter to Diyarbekir, while the Khan of Crimea, Canibek Giray, attacked the areas of Ganja, Nakhichevan and Julfa.
Capitulations and trade treaties
Ahmed I renewed trade treaties with England, France and Venice. In July 1612, the first ever trade treaty with the Netherlands was signed. He expanded the capitulations given to France, specifying that merchants from Spain, Portugal, Catalonia, Ragusa, Genoa, Ancona and Florence could trade under the French flag.
Architect and Service to Islam
Sultan Ahmed constructed the Sultan Ahmed Mosque, the magnum opus of the Ottoman architecture, across from the Ayasofya mosque. The Sultan attended the breaking of the ground with a golden pickaxe to begin the construction of the mosque complex. An incident nearly broke out after the Sultan discovered that the Blue Mosque contained the same amount of minarets as the grand mosque of Mecca. Sultan Ahmed became furious at this fault and became remorseful until the Shaykh-ul-Islam recommended that he should erect another Minaret at the grand mosque of Mecca and the matter was solved.
Sultan Ahmed became delightedly involved in the eleventh comprehensive renovations of the Ka’ba, which had just been damaged by flooding. He sent craftsmen from Istanbul, and the golden rain gutter that kept rain from collecting on the roof of the Ka’ba was successfully renewed. It was again during the era of Sultan Ahmed that an iron web was placed inside the Well of Zamzam in Mecca. The placement of this web about three feet below the water level was a response to lunatics who jumped into the well, imagining a promise of a heroic death.
In Medina, the city of the Prophet Muhammad, a new pulpit made of white marble and shipped from Istanbul arrived in the mosque of the Prophet and substituted the old, worn – out pulpit. It is also known that Sultan Ahmed erected two more mosques in Uskudar on the Asian side of Istanbul; however neither of them have survived.
The Sultan had a crest carved with the footprint of the Prophet Muhammad which he would wore during Fridays and on festive days and illustrated one of the most significant examples of affection to the prophet in Ottoman History. Engraved inside the crest was a poem he composed:
“If only could I bear over my head like my turban forever thee, If only I could carry it all the time with me, on my head like a crown, the Footprint of the Prophet Muhammad, which has a beautiful complexion, Ahmed, go on, rub your face on the feet of that rose.“
Ahmed I's mother was Valide Handan Sultan, an ethnic Greek who was originally named Helena. He was born at Manisa Palace. He succeeded his father Mehmed III (r. 1595–1603) in 1603 at age 13. He broke with the traditional fratricide and sent his brother Mustafa to live at the old palace at Bayezit along with their grandmother Safiye Sultan. He was known for his skills in fencing, poetry, horseback riding, and fluency in numerous languages. A far lost uncle of Ahmed, Yahya, resented his accession to the Ottoman throne in 1603, and spent his life scheming to become Sultan.
Ahmed was a poet who wrote a number of political and lyrical works under the name Bahti. But while supportive of poetry, he displayed an aversion to artistry and continued his father's neglect of miniature painting. This was connected to a devout religiosity that declared depiction of living things in art an immoral rivalry to Allah's creation.Accordingly, Ahmed patronized scholars, calligraphers, and pious men. Hence he commissioned a book entitled The Quintessence of Histories to be worked upon by calligraphers. He also attempted to enforce conformance to Islamic laws and traditions, restoring the old regulations that prohibited alcohol and he attempted to enforce attendance at Friday prayers and paying alms to the poor in the proper way.
He was responsible for the destruction of the musical clock organ that Elizabeth I of England sent to the court during the reign of his father. The reason for this may have been Ahmed's religious objection to figurative art or the fact that the complex organ served as a daily reminder of the waxing influence and power of the West.
Ahmed I died of typhus and gastric bleeding in 1617.
Marriages and issue
• Osman II (3 November 1604 - 20 May, 1622), we reserved with Hatice.
• Prince Mehmed (8 March 1605 - murdered 12 January 1621), with Mahpeyker Kösem Sultan. Crown Prince since 1618.
• Prince Orhan (1609-1612).
• Prince Cihangir (born and died 1609).
• Prince Selim (27 June 1611-27 July 1611).
• Murad IV (26/27 July 1612 – 8 February 1640), with Mahpeyker Kösem.
• Prince Hasan (25 November 1612-1615).
• Prince Bayezid (December 1612 - murdered 27 July 1635); bec but Crown Prince in 1623.
• Prince Hussein (14 November 1613-1617).
• Prince Kasim (early 1614-17 February 1638), the last with Mahpeyker Kösem; Crown Prince since 1635.
• Prince Suleiman (5 November 1615 - murdered 27 July 1635), with Mahpeyker Kösem.
• Ibrahim I (5 November 1615 – 18 August 1648), with Mahpeyker Kösem.
• Ayse Sultan (end 1605 - Mayer 1657) Free, with Mahpeyker Kösem. Married:
• Firstly four in March 1612, Nasir Pasha Gumulkineli law .
• Sekndli 1615, son Shahid Muhammad Pasha Caracas.
• Thirdly XIII in March 1627, son of Hafiz Ahmed Pasha Muazrzinzde martyr .
• fourthly 1 March 1632, Damad Murtaza Pasha.
• fifthly 1637, Damas drive Moving Ahmed Pasha.
• sixthly March 1645, Damad Ahmed Pasha.
• seventhly 28 February 1655, Abaza Ibsen Damad Mustafa Pasha.
• Aithli December 1656, the son of Solomon Pasha searched.
• Fatma Sultan (1606 – 1670), with Mahpeyker Kösem. Married:
• firstly 13 July 1626, Damad Kara Mustafa Pasha, Governor of Egypt 1624-1625.
• Sekndli 1629, son Stkli Hassan Pasha.
• 1632 Thirdly, Canbuladza Damad Mustafa Pasha.
• Forthli (Div.) 1637, son Yusuf Pasha searched, 1628-1634 Vizir.
• fifthly Damad Maksud Pasha (k. September 1644), Governor of Diyarbekr 1640-1641 and Egypt 1642-1644.
• Sikthly six in April 1662, son Abza owner Ahmed Pasha Gazi .
• seventhly April 1663, Damad Agha Mustafa Pasha, Cdr. of the Janissary Corps 1658, Governor of Damascus 1662-1663, Baghdad 1663, Maras, Tarabulsi and Egypt.
• Handan Sultan (born 1607?). 
• Hatice Sultan (1608-1610).
• Gevherhan Sultan (1608 - 1660), with Mahpeyker Kösem. Married:
• firstly 1619, Damad Kara Okuz Muhammad Pasha, Vizier in 1606, 1614-1616 and 1619.
• Sekndli 1624, are Topl son Rajib Pasha , in 1624 Vizir.
• Hanzade Sultan (1609-21 September 1650), with Mahpeyker Kösem.  Married April 1622, Damad Ladikl Bayram Pasha , Vizier in 1622 and 1637-1638.
• Esma Sultan (born and died 1612).
• Zahide Sultan (born bef. November 1613 to 1620). 
• Burnaz Makeup Sultan (1614 - 1674), with Mahpeyker Kösem. married:
• firstly 1630, Damad Ja'afar Pasha, sometime Gentleman-in-waiting to the Sultan.
• secondly 1648, Damad Koja Sofu Kenan Pasha, sometime gentleman-in-waiting to the Sultan and Vezir.
• thirdly July 1652, Damad Yusuf Pasha, Lord High Falconer, Vizier 1652 and Cdt. of Tuna fortress 1664-1666.
• Zeynep Sultan (1617-1619). 
• Abide Sultan (born posthumously, 1618 – 1675). Married 1642, Damad Kucuk Musa Pasha, Vizier in 1640, and later Governor of Rumelia and Baghdad.
Bilingual Franco-Turkish translation of the 1604 Franco-Ottoman Capitulations between Ahmed I and Henry IV of France, published by François Savary de Brèves in 1615.
Today, Ahmed I is remembered mainly for the construction of the Sultan Ahmed Mosque (also known as the Blue Mosque), one of the masterpieces of Islamic architecture. The area in Fatih around the Mosque is today called Sultanahmet. He died at Topkapı Palace in Istanbul and is buried in a mausoleum right outside the walls of the famous mosque.