Gerhard I, Count of Holstein-Itzehoe

Gerhard I, Count of Holstein-Itzehoe
Seal of Gerhard I, which he used from 1254 to 1287
Spouse(s)	Elizabeth of Mecklenburg Adelaide of Montferrat
Noble family	House of Schauenburg
Father	Adolf IV of Holstein
Mother	Heilwig of Lippe
Born	1232
Died	21 December 1290(1290-12-21)

Gerhard I, Count of Holstein-Itzehoe (1232 – 21 December 1290) was the only count of Holstein-Itzehoe.

He was the second son of Count Adolf IV of Holstein and Heilwig of Lippe.

When his father retired to a monastery in 1238, he ruled the Holstein jointly with his elder brother John I, initially under the guardianship of their uncle the Duke Abel of Schleswig. When they came of age, the brothers took up government and continue their joint rule. In 1255, they concluded a trade agreement with Lübeck.

When their father died in 1261, John and Gerhard divided Holstein. Gerhard took Holstein-Itzehoe, consisting of the districts of Stormarn, Plön and Schaumburg, with his residence in Itzehoe. John received Holstein-Kiel, consisting of the districts Kiel, Wagria and East Holstein, with his seat in Kiel. John later won Rendsburg back from Denmark and traded it with Gerhard for Segeberg.

Gerhard founded several villages, in order to develop Holstein and control the area. He also developed the County's administration. He fought ward with the Archdiocese of Bremen, th City of Lübeck and the landed genry in his county. In 1262, he won the Battle of the Loh Moor. In 1263, John died and Gerhard became regent of Kiel and Segeberg for John's sons.

Gerhard I died in 1290. After his death, his sons subdivided Holstein-itzehoe into Holstein-Plön, Holstein-Pinneberg and Holstein-Rendsburg.