Osaka Castle (大坂城 Ôsakajô) is a castle in Chuo-ku, Osaka, Japan.

Originally called Ozakajo, it is one of Japan's most famous castles, and played a major role in the unification of Japan during the 1500's.

The castle is situated on a plot of land roughly one kilometer square. It is built on two raised platforms of landfill supported by sheer walls of cut rock, each overlooking a moat. The central castle building is five stories on the outside and eight stories on the inside, and built atop a tall stone foundation to protect its occupants from sword-bearing attackers.

History

• 1583: Toyotomi Hideyoshi commenced construction on the site of the Ikko Ikki temple of Honganji. The basic plan was modeled after Azuchi Castle, the headquarters of Oda Nobunaga. Toyotomi wanted to build a castle that mirrored Oda's, but surpassed it in every way: the plan featured a five-story main tower, with three extra stories underground, and gold leaf on the sides of the tower to impress visitors.
• 1585: Inner donjon completed. Toyotomi continued to extend and expand the castle, making it more and more formidable to attackers.
• 1598: Construction completed.
• 1603: Tokugawa Ieyasu defeated Toyotomi at the Battle of Sekigahara, and started his own bakufu in Edo. Toyotomi died and passed on control of Osaka Castle to his son, Toyotomi Hideyori.
• 1614: Tokugawa attacked Toyotomi in the winter. Although Toyotomi's forces were outnumbered 2 to 1, he managed to fight off Tokugawa's 200,000-man army and protect the castle's outer walls. However, Tokugawa attempted to muzzle Toyotomi by filling up the castle's outer moat, rendering it largely defenseless.
• 1615: During the summer, Toyotomi began to dig the outer moat once more. Tokugawa, in outrage, sent his armies to Osaka Castle again, and routed Toyotomi's men inside the outer walls. Osakajo fell to Tokugawa, and the Toyotomi clan disappeared.
• 1620: The new heir to the shogunate, Tokugawa Hidetada, began to reconstruct and rearm Osaka Castle. He built a new elevated main tower, five stories on the outside and eight stories on the inside, and assigned the task of constructing new walls to individual samurai clans. The walls built in the 1620's still stand today, and are made out of interlocked granite boulders with no mortar whatsoever: they are held together solely by each other. Many of the stones were brought from rock quarries in the Seto Inland Sea, and bear inscribed crests of the various families who laid them into the walls.
• 1665: Lightning strikes burned down the main tower.
• 1843: After decades of neglect, the castle got much-needed repairs when the bakufu collected money from the people of the region to rebuild several of the turrets.
• 1868: Much of the castle was burned in the civil conflicts surrounding the Meiji Restoration. Under the Meiji government, Osaka Castle was converted to a barracks for Japan's rapidly-expanding Western-style military.
• 1928: The main tower was restored after the mayor of Osaka concluded a highly successful fund-raising drive.
• 1945: Bombing raids on Osaka damaged the reconstructed main tower.
• 1995: Osaka's government approved yet another restoration project, with the intent of restoring the main tower to its Edo-era splendor.
• 1997: Restoration was completed.

The castle is open to the public, and is easily accessible from Osakajo Koen Station on the JR Osaka Loop Line. It is a popular spot during festival seasons, and especially during the cherry blossom bloom, when the sprawling castle grounds are covered with food vendors and taiko drummers.