| Agnes of Brunswick-Grubenhagen | |
| Alt: | See caption |
| House: | House of Guelph |
| Father: | Eric I, Duke of Brunswick-Grubenhagen |
| Mother: | Elisabeth of Brunswick-Göttingen |
| Burial Place: | Abbey church in Gandersheim Abbey |
Agnes of Brunswick-Grubenhagen (born: ; died: 18 November 1439) was, from 1412 to 1439, abbess of Gandersheim Abbey as Agnes II.
She was a daughter of Eric I, Duke of Brunswick-Grubenhagen. She was about six years old when she was elected abbess of Gandersheim Abbey. The pope confirmed Agnes's election while she was a minor, however, he appointed a dean of the Abbey as her guardian and regent. Around 1425, Agnes began to rule without a regent.
She died in 1439 and was buried in the abbey church.
In connection with the Guelph inheritance division[1] after the Lords of Homburg died out, she transferred the castle and town of Gandersheim and the castles of Seesen and Stauffenburg to Otto II of Brunswick-Göttingen. She transferred Asseburg Castle, Gifhorn, Castle and City of Lüneburg, Greene Castle, Lüthorst, one half of the fief of Homburg, Lauenstein Castle, and the former County of Wernigerode to William I of Brunswick-Wolfenbüttel.[2]