Margaret I of Denmark was a significant historical figure who reigned in the late 14th and early 15th centuries. Born in 1353, she became the Queen of Denmark, Norway, and Sweden, uniting these kingdoms under the Kalmar Union. Her reign marked a period of relative peace and stability in Scandinavia. Margaret was known for her strong leadership and political acumen. After the death of her son, she adopted her grandnephew, Erik of Pomerania, as her heir. She ruled until her death in 1412, leaving a lasting legacy as one of the first female monarchs in Northern Europe.