5 things to know as Japan's Emperor Akihito steps down

A who’s who of Japan’s royal family, the world’s oldest monarchy Everything you need to know about the Japan's royal family as things are about to change on the Chrysanthemum throne.

Japanese Emperor Akihito announced his abdication from the throne on Tuesday in his final address, marking the official transition from the “Heisei Era,” to the “Reiwa Era.” Heisei means “achieving peace.” Reiwa translates to “beautiful harmony.”

Akihito, 85, said in 2016 that he would hand over the throne to his elder son, Crown Prince Naruhito, 59, after 30 years. It marks the first time in 200 years that an emperor has abdicated the throne.

Akihito's reign ends at midnight Tuesday, after which Naruhito will ascend the throne as new emperor.

Here are five things to know about Japan’s historic change.

1. The imperial bloodline goes back more than 1,500 years

Akihito is officially recognized as the 125th Emperor of Japan, and considered a direct descendant of Japan's first emperor, Jimmu, who is said to have ascended the throne in 660 BC.

Historical evidence suggests the bloodline goes back at least 96 emperors, to Kinmei, who ascended the throne 1,510 years ago, in 509 AD.

Japanese legend posits that emperors are direct descendants of the sun goddess Amaterasu Omikami, but Akihito has never made that claim.

2. Akihito’s reign marked a break from Japan’s militaristic era

Akihito inherited the throne from his father, Emperor Hirohito, who reigned over Japan from 1926 until 1989. Hirohito oversaw a tumultuous period that included imperial aggression, the attack on Pearl Harbour, and the U.S. atomic bombings of Hiroshima and Nagasaki.

Soon after his ascension, Akihito offered an apology to South Korean President Roh Tae-woo, saying that “I cannot help but feel the deepest remorse, thinking of the pain your people suffered during the sorrowful years brought about by my country.”

During a state visit to China in 1992, Akihito did not directly apologize for atrocities committed by the Japanese army but expressed “deepest sorrow” for “an unfortunate time during which my country caused great pain and suffering.”

3. Akihito and his wife, Empress Michiko, modernized the monarchy

The Imperial Household Agency came up with a list of 800 women who would be suitable for Akihito to marry. He ignored the list and chose commoner Michiko Shoda instead. They wed in 1959.

The couple broke with tradition again by raising their three children, rather than giving them over to palace aids.

They also began a new tradition: kneeling with the public in difficult times, including after the 2011 earthquake and nuclear disaster.

They have two sons, Crown Prince Naruhito and Prince Fumihito.

4. Crown Prince Naruhito married to economist Masako Owada

Naruhito was the first in his family to study abroad, attending Oxford University. He took history and wrote a memoir that included a tour of 21 historic pubs along the Thames River.

In 1993, he married Masako Owada, a Harvard-trained economist who went to work for the Ministry of Foreign Affairs in 1986 after being just one of 28 out of 800 people to pass the entrance exam.

Owada has struggled with the pressure of royalty, and has been diagnosed with an “adjustment disorder,” which is related to depression and anxiety.

The couple had one child, daughter Aiko, in 2001.

Ancient protocol means that Owada will not be allowed to witness the sacred handover ceremony on May 1, when Naruhito will receive a sword, a jewel and official seals.

5. Naruhito is being welcomed with a 10-day holiday

Japanese workers typically have five days off this time of year, known as the Golden Week.

In honour of the ascension ceremony, the holiday period has been extended to 10 days.

Some Japanese plan to uncork champagne and eat imperial-themed sweets on Wednesday, even though Naruhito will not be formally announced as emperor until Oct. 22.

With files from The Associated Press and CNN