During the early years of Ibrahim's reign, he retreated from politics and turned increasingly to his harem for comfort and pleasure. During his sultanate, the harem achieved new levels of luxury in perfumes, textiles and jewellery. His love of women and furs led him to have a room entirely lined with lynx and sable. Because of his infatuation with furs, the French dubbed him "Le Fou de Fourrures." Kösem Sultan kept her son in check by supplying him with virgins she personally purchased from the slave market, as well as overweight women, for whom he craved.^[41]

Kara Mustafa Pasha remained as Grand Vizier during the first four years of Ibrahim's reign, keeping the Empire stable. With the treaty of Szön (15 March 1642) he renewed peace with Austria and during the same year recovered Azov from the Cossacks. Kara Mustafa also stabilized the currency with coinage reform, sought to stabilize the economy with a new land-survey, reduced the number of Janissaries, removed non-contributing members from the state payrolls, and curbed the power of disobedient provincial governors. During these years, Ibrahim showed concern with properly ruling the empire, as shown in his handwritten communications with the Grand Vizier.

Ibrahim came under the influence of various unsuitable people, such as mistress of the imperial harem Şekerpare Hatun and the charlatan Cinci Hoca, who pretended to cure the Sultan's physical ailments. The latter, along with his allies Silahdar Yusuf Agha and Sultanzade Mehmed Pasha, enriched themselves with bribes and eventually usurped enough power to secure the execution of Grand Vizier Ḳara Muṣṭafā. Cinci Hoca became Kadiasker (High Judge) of Anatolia, Yusuf Agha was made Kapudan Pasha (Grand Admiral) and Sultanzade Mehmed became Grand Vizier.^[42]

In 1644, Maltese corsairs seized a ship carrying high-status pilgrims to Mecca. Since the pirates had docked in Crete, Kapudan Yusuf Pasha encouraged Ibrahim to invade the island. This began a long war with Venice that lasted 24 years—Crete would not completely fall under Ottoman domination until 1669. In spite of the decline of La Serenissima, Venetian ships won victories throughout the Aegean, capturing Tenedos (1646) and blockading the Dardanelles.

Mass discontent was caused by the Venetian blockade of the Dardanelles—which created scarcities in the capital—and the imposition of heavy taxes during a war economy to pay for Ibrahim's whims. In 1647 the Grand Vizier Salih Pasha, Kösem Sultan, and the şeyhülislam Abdürrahim Efendi unsuccessfully plotted to depose the sultan and replace him with one of his sons. Salih Pasha was executed, and Kösem Sultan was exiled from the harem. The next year, the Janissaries and members of the ulema revolted. On 8 August 1648, corrupt Grand Vizier Aḥmed Pasha was strangled and torn to shreds by an angry mob, gaining the posthumous nickname "Hezarpare" ("thousand pieces"). On the same day, Ibrahim was seized and imprisoned in Topkapı Palace. Kösem gave consent to her son's fall, saying "In the end he will leave neither you nor me alive. We will lose control of the government. The whole society is in ruins. Have him removed from the throne immediately." Ibrahim's six-year-old son Meḥmed was made sultan. Ibrahim was strangled on 18 August 1648. His death was the second regicide in the history of the Ottoman Empire.