Safavid Empire

The Safavid Iran or the Safavid Empire (Persian: شاهنشاهی صفوی, Šāhanšāhi-ye Safavi), was an early modern Iranian empire established by a dynasty of native Iranian, probably Kurdish origin, which was culturally Turkified. The period of the Safavids, the dynasty that took control of Persia in the early 16th century, is often considered the beginning of modern Iranian history, just as the state they created is said to mark the genesis of the Iranian nation-state. 
The Safavids ruled from 1501 to 1722 (experiencing a brief restoration from 1729 to 1736 and 1750 to 1773) and, at their height, they controlled all of what is now Iran, Republic of Azerbaijan, Bahrain, Armenia, eastern Georgia, parts of the North Caucasus including Russia, Iraq, Kuwait, and Afghanistan, as well as parts of Turkey, Syria, Pakistan, Turkmenistan, and Uzbekistan.
History.
Safavid conquest of Iran.
Safavids were originally a family of Sufi Safavid order and of Kurdish origin, they were culturally Turkified and spoke Ajemi Turkic but were still Iranians. In the summer of 1500, Ismail (member of Safavid family), rallied about 7,000 Qizilbash troops at Erzincan, including members of the Ustajlu, Rumlu, Takkalu, Dhu'l-Qadar, Afshar, Qajar, and Varsaq. Qizilbash forces passed over the Kura River in December 1500, and marched towards the Shirvanshah's state. They defeated the forces of the Shirvanshah Farrukh Yassar near Cabanı (present-day Shamakhi Rayon, Azerbaijan Republic) or at Gulistan (present-day Gülüstan, Goranboy, Nagorno-Karabakh), and subsequently went on to conquer Baku.
Thus, Shirvan and its dependencies (up to southern Dagestan in the north) were now Ismail's. The successful conquest had alarmed the ruler of the Aq Qoyunlu, Alvand, who subsequently proceeded north from Tabriz, and crossed the Aras River in order to challenge the Safavid forces, and both sides met at the battle of Sharur in which Ismail's army came out victorious despite being outnumbered by four to one. He also made an alliance with the Kurds of Dersim, even though he had bad relations with other Kurds. In July 1501, Ismail was enthroned as Shah of Iran choosing Tabriz as his capital. He appointed his former guardian and mentor Husayn Beg Shamlu as the "vakil" (vicegerent) of the empire and the commander-in-chief ("amir al-umara") of the Qizilbash army.
Revival of Iranianhood and spread of Shi'ism.
The reign of Ismail I is one of the most important in the history of Iran. The reasons for this are twofold. Firstly, before his accession in 1501, Iran, since its conquest by the Arabs eight-and-a-half centuries earlier, had not existed as a unified country under native Iranian rule, but had been controlled by a series of Arab caliphs, Turkic sultans, and Mongol khans. Although many Iranian dynasties rose to power amidst this whole period, it was only under the Buyids that a vast part of Iran properly returned to Iranian rule (945–1055). Secondly, one of his first acts, the promulgation of the Eṯnā-ʿašarī rite of Shiʿism to be the official religion of the newly-created state, had profound consequences for the subsequent history of Iran.
After the Ismail I.
In the reign of Tahmasb I, Suleiman the Magnificent (r. 1520–1566), sultan of the Ottoman Empire, may have considered a strong Safavid empire a threat to his ambitious plans in the west and northwest of his realm. During the first decade of Tahmasp's reign, however, he was preoccupied with fighting the Habsburgs and the unsuccessful attempt to seize Vienna. In 1532, while the Ottomans were fighting in Hungary, Suleiman sent Olama Beg Takkalu with 50,000 troops under Fil Pasha to Iran. The Ottomans seized Tabriz and Kurdistan, and tried to obtain support from Gilan province. Tahmasp drove the Ottomans out, but news of another Uzbek invasion prevented him from defeating them. Suleiman sent his grand vizier, Ibrahim Pasha, to occupy Tabriz in July 1534 and joined him two months later. Suleiman peacefully conquered Baghdad and Shia cities such as Najaf. Whilst the Ottomans were on the march, Tahmasp was in Balkh, campaigning against the Uzbeks. Tahmasp did not fight the exhausted Ottoman army but laid waste the entire region from Tabriz to the frontier; the Ottomans could not permanently occupy the captured lands, since they soon ran out of supplies. 
Ismail II reigned for one year and was replaced by Mohammad Khodabanda. At the time of Mohammad Khodabanda, oreign powers took advantage of the factional discord in Iran court to seize territory for themselves. Uzbek bands attempted to invade north-east Iran before being repulsed by the governor of Mashhad. The most important event of Khodabanda's reign was the war with the Ottomans. In 1578, the Ottoman sultan Murad III began a war with Safavid Iran which was to last until 1590. In the first attack, the sultan's vizier Lala Mustafa Pasha invaded the Safavid territories comprising Georgia and Shirvan. Shirvan fell before the end of the summer of 1578, by which fact the Ottomans had now control of almost all territories west of the Caspian Sea coast, and it also opened the way for an attack on what is nowadays the core of Armenia and Azerbaijan, which were subsequently attacked in 1579 by a large contingent of Crimean Tatars, led by Adil Giray Khan, but he was captured in a remarkable counterattack led by Mirza Salman Jabiri and Hamza Mirza, and later executed in Qazvin, the Safavid capital at that time.
Reconquest.
Against the Uzbeks
His successor, Abbas I, initiated a Reconquest, with the Uzbeks invading Khorasan first. By 1599, Abbas had conquered not only Herat and Mashhad, but had moved as far east as Balkh. This would be a short-lived victory and he would eventually have to settle on controlling only some of this conquest after the new ruler of the Khanate of Khiva, Baqi Muhammad Khan attempted to retake Balkh and Abbas found his troops were still no match for the Uzbeks. By 1603, the battle lines had stabilized, albeit with the loss of the majority of the Persian artillery. Abbas was able to hold onto most of Khorassan, including Herat, Sabzevar, Farah, and Nisa.
Abbas' north-east frontier was now safe for the time being and he could turn his attention to the Ottomans in the west. After defeating the Uzbeks, he moved his capital from Qazvin to Isfahan.
Against the Ottomans
He then fought against the Ottomans and aptured northern Iran even in 1623, Abbas decided to take back Mesopotamia, which had been lost by his grandfather Tahmasp through the Ottoman-Safavid War (1532–1555). Profiting from the confusion surrounding the accession of the new Ottoman Sultan Murad IV, he pretended to be making a pilgrimage to the Shi'ite shrines of Kerbala and Najaf, but used his army to seize Baghdad. However, Abbas was then distracted by a rebellion in Georgia in 1624 led by Giorgi Saakadze thus allowing an Ottoman force to besiege Baghdad, but the Shah came to its relief the next year and crushed the Turkish army decisively. At the same time he remained engaged in the north, reconquering Azerbaijan and chasing the Ottomans out of Naḵjavān, Erevan, Lorestān and part of Kurdistan. In 1607 he took Širvān as well as parts of Georgia. In later years, ʿAbbās recaptured Kandahar, consolidated his access to the Persian Gulf coast by driving the Portuguese out of Hormuz, regained parts of Kurdistan, and seized important portions of Mesopotamia, including Baghdad. In 1638, however, after Abbas' death, the Ottomans retook Baghdad, and the Iranian–Ottoman border was finalised to be roughly the same as the current Iran–Turkey and Iran–Iraq borders.
Fall.
Safavids eventually succumbed to Russian, Afghan and Ottoman pressure and was replaced by Afsharids.