Oberägeri first appears in historical documents in 1150 as Agregia.
 In 1538 it was mentioned as Ober Egere.

The first church in the valley was built in 876.
After 1100, the land belonged to the monastery of Einsiedeln, and was influenced by the Battle of Morgarten.

The Battle of Morgarten occurred on 15 November 1315 at Morgarten (now part of Oberägeri) and near neighboring Sattel.
 It began when a Swiss Confederation force of 1,500 infantry archers, led by Werner Stauffacher, ambushed a group of Austrian soldiers of the Holy Roman Empire under the command of Duke Leopold I of Austria near the Morgarten Pass.
The Swiss thoroughly defeated the Austrians.

The Confederates prepared a road-block and an ambush at a point between Lake Aegeri and Morgarten Pass where a small path led between the steep slope and a swamp.
When about 1500 men attacked from above with rocks, logs and halberds, the Austrian knights had no room to defend themselves and suffered a crushing defeat, while the foot soldiers in the rear fled back to the city of Zug.
A chronicler described the Confederates, unfamiliar with the customs of battles between knights, as brutally butchering everything that moved and everyone unable to flee.
This founded the reputation of the Confederates as barbaric, yet fierce and respectable fighters.

Within a month of the battle, in December 1315, the Confederates renewed the oath of alliance made in 1291, initiating the phase of growth of the Old Swiss Confederacy.

Within forty years, cities including Lucerne, Zug, Zürich and Bern had joined the confederation.

The victory of the Confederates left them in virtual autonomy and gave them a breathing-space of some sixty years before the next Habsburg attack resulted in the Battle of Sempach (1386).

The municipality came into existence in the 15th century.
Around 1500, several chapels and the first government building were built in Oberägeri.
In 1669 the municipality gained the right to elect its own priest.
In 1726 the church was burgled.
In 1766 the governments of Oberägeri and Unterägeri (at the time known as Wilägeri) became involved in an open fight during local parliamentary sessions, and the two municipalities split in 1798.

In 1838 the city of Zurich stopped collecting interest they had had a right to since medieval times.
In the same year the first school-building in the municipality was built.
The second school was not built until 1956.

Water supplies were established in 1890 by a local pub landlord.
Oberägeri first appears in historical documents in 1150 as Agregia.  In 1538 it was mentioned as Ober Egere.
The first church in the valley was built in 876. After 1100, the land belonged to the monastery of Einsiedeln, and was influenced by the Battle of Morgarten.
The Battle of Morgarten occurred on 15 November 1315 at Morgarten (now part of Oberägeri) and near neighboring Sattel.  It began when a Swiss Confederation force of 1,500 infantry archers, led by Werner Stauffacher, ambushed a group of Austrian soldiers of the Holy Roman Empire under the command of Duke Leopold I of Austria near the Morgarten Pass. The Swiss thoroughly defeated the Austrians.
The Confederates prepared a road-block and an ambush at a point between Lake Aegeri and Morgarten Pass where a small path led between the steep slope and a swamp. When about 1500 men attacked from above with rocks, logs and halberds, the Austrian knights had no room to defend themselves and suffered a crushing defeat, while the foot soldiers in the rear fled back to the city of Zug. A chronicler described the Confederates, unfamiliar with the customs of battles between knights, as brutally butchering everything that moved and everyone unable to flee. This founded the reputation of the Confederates as barbaric, yet fierce and respectable fighters.
Within a month of the battle, in December 1315, the Confederates renewed the oath of alliance made in 1291, initiating the phase of growth of the Old Swiss Confederacy.
Within forty years, cities including Lucerne, Zug, Zürich and Bern had joined the confederation.
The victory of the Confederates left them in virtual autonomy and gave them a breathing-space of some sixty years before the next Habsburg attack resulted in the Battle of Sempach (1386).
The municipality came into existence in the 15th century. Around 1500, several chapels and the first government building were built in Oberägeri. In 1669 the municipality gained the right to elect its own priest. In 1726 the church was burgled. In 1766 the governments of Oberägeri and Unterägeri (at the time known as Wilägeri) became involved in an open fight during local parliamentary sessions, and the two municipalities split in 1798.
In 1838 the city of Zurich stopped collecting interest they had had a right to since medieval times. In the same year the first school-building in the municipality was built. The second school was not built until 1956.
Water supplies were established in 1890 by a local pub landlord.
Oberägeri