Anegawa: The Day Oichi's Brother and Husband Became Enemies

On June 28, 1570 (the twenty-eighth of the sixth month of Genki 1), at the Ane River in Ōmi Province (modern Nagahama City, Shiga Prefecture).

The allied force of Oda Nobunaga and Tokugawa Ieyasu — 28,000 — faced the allied force of Azai Nagamasa and Asakura Yoshikage — 18,000.

Both armies deployed across the flow of the Ane River, and fierce combat continued from morning to evening.

To Nobunaga, Nagamasa was his sister's husband; to Nagamasa, Nobunaga was his brother-in-law.

The two houses, tied by political marriage three years before, on this day fully entered a relationship of hostility.

Around 1567, Nobunaga married his sister Oichi to Azai Nagamasa. The aim was to conclude an alliance between the Azai of northern Ōmi and the Oda of Owari-Mino.

Oichi was around twenty, Nagamasa around twenty-two. Their smooth married life was tossed by the political conflict between Nagamasa's father Hisamasa and his father-in-law Nobunaga.

In 1570, when Nobunaga attacked Asakura Yoshikage of Echizen, the Azai gave priority to their generational pledge with the Asakura and sided with the Asakura.

The Azai betrayal that tried to pincer Nobunaga at the Battle of Kanegasaki became one of the greatest crises of Nobunaga's life.

At this time, Oichi is said to have delivered to Nobunaga a 'bag of azuki beans tied at both ends,' hinting at the Azai betrayal — such is the anecdote widely told from the Edo period onward.

But it has no corroboration in contemporary sources. The course by which Nobunaga sensed the Azai betrayal appears in the sources, but there is no concrete evidence showing Oichi's involvement.

The current view of research is that it is a tradition created by Edo-period story authors to emphasize the tragedy of a woman whose real brother and real husband became enemies.

At Anegawa the Asakura-Azai allied force was defeated, but the Azai house withdrew to their home Odani Castle and continued to resist.

For three years thereafter, Nobunaga gradually reduced the Azai power, and in August 1573 he brought Odani Castle to fall.

During those three years, Oichi and the three sisters lived inside Odani Castle, surrounded by her real father's retainers who had been defeated by her real brother at Anegawa.

Her real brother killing her real husband's retainers, her real husband's retainers fighting her real brother's army — Oichi's three years became the case that most vividly showed the position of women when Sengoku-period political marriage collapsed.