Teedyuscung was born around 1700, probably near present-day Trenton, New Jersey, into a Lenape community living amid accelerating European settlement. The names of his parents and details of his childhood are not securely recorded. His lifetime began during a period when Lenape families were being displaced from older homelands along the Delaware River by colonial land purchases, migration, and the expanding authority claimed by Pennsylvania and New Jersey.

As a young man, Teedyuscung moved westward and northward with other Lenape people. He lived for a time near the Forks of the Delaware and later became associated with the Wyoming Valley along the Susquehanna. He converted to Moravian Christianity in the 1740s and was baptized as Gideon, though his relationship with missionaries was complex and did not erase his political independence or traditional obligations. He struggled at times with alcohol, a fact emphasized by colonial observers but inseparable from the destructive effects of the colonial trade.

Teedyuscung developed influence as an forceful speaker and negotiator. Colonial officials called him a king, but his authority depended on persuading communities and representing their grievances rather than commanding them. He resented the Walking Purchase of 1737 and other transactions through which Pennsylvania obtained Lenape land. He also resisted Haudenosaunee claims to speak for all Delaware people.

By the opening of the French and Indian War, Teedyuscung had become a prominent advocate for communities caught between competing empires. British settlement threatened their lands, while French alliances offered weapons and leverage but no guarantee of independence. He initially participated in resistance against Pennsylvania before turning toward negotiation. His early experiences of removal, missionary contact, trade, and unequal diplomacy prepared him to confront colonial leaders at the Easton conferences and demand recognition of Lenape grievances.