Dummer was born into a wealthy Massachusetts merchant family, traveling to England as a young man to participate in the business.

Upon his return to Massachusetts in 1712 he entered provincial politics, gaining a royal commission as lieutenant governor through the efforts of his brother Jeremiah.

[1] His grandfather was Richard Dummer, an early Massachusetts settler and one of the colony's wealthiest men, and he was also related to the magistrate Samuel Sewall.

[10] In a gift that may have been made in anticipation of his wedding, his father in November 1712 gave him a substantial tract of land in the Byfield section of Newbury.

This resulted in a political scramble for appointments to the leadership of Massachusetts between Dudley's supporters and proponents of a land bank proposal designed to deal with inflationary issuance of colonial currency.

Although he was unable to secure Dudley's reappointment, he and Jonathan Belcher were able to bribe the successor chosen by the land bank faction, Elizeus Burges, to give up his commission.

[16] Because of the ongoing disputes with the assembly, Shute abruptly left the province for London on January 1, 1723, leaving Dummer to act as governor and commander-in-chief.

In both of these he was unsuccessful: the Iroquois, despite significant financial inducements, refused to take up arms against tribes seen to be allied with New France, or to engage in a conflict in which they had no stake.

[19] In August 1723 Grey Lock began raiding Massachusetts frontier communities in the Connecticut River valley, taking captives and inflicting casualties at Northfield.

Embassies sent by Indian commissioners in Albany, New York and by eastern Abenaki leaders failed to make contact with the warrior, and he disappeared from view.

[28] After Norridgewock was destroyed in a third raid in August 1724 (an action in which the influential French Jesuit priest Sebastian Rale was killed), the war died down.

He refused in principle to halt settlement activities in contested territories, but allowed the Penobscots to retain a Roman Catholic priest.

[31] The Penobscots, despite their reservations, promoted this peace within the confederacy, and reported in March 1727 that all of the tribes except Grey Lock's band had agreed to it.

[32] A final major peace conference held at Casco Bay in July 1727 formally closed hostilities, and included Dummer, New Hampshire's Acting Governor John Wentworth, Nova Scotia's military commander Paul Mascarene, and many representatives of the Wabanaki Confederacy.

[31][32] The treaty that Dummer negotiated became a staple of diplomacy between Massachusetts and the eastern tribes despite the discrepancies between written and oral versions.

[34] Dummer sought to be generally conciliatory in his dealings with the provincial legislature,[35] tolerating, for example, the selection of Elisha Cooke (who had led the opposition to Shute) as speaker of the assembly.

[36][37] He finessed the assembly's attempts to interfere with management of the militia by organizing expeditions when the body was not in session, earning the enmity of opponents when it did meet.

The assembly proposed to circumvent the need for an exception by allocating the issue for the repair of fortifications, something for which Dummer had requested funding.

Since the proposed currency issuance greatly exceeded the amount needed for repairs, Dummer vetoed the request and dissolved the assembly.

[46] He remained in office until June 11, 1730, when he was replaced by William Tailer, who had been selected by incoming Governor Jonathan Belcher as his lieutenant.

[53] In July 2006 it changed to The Governor's Academy (the benefactor's surname sounded uncomfortably like "dumber," it was decided, and thus elicited predictable taunts during sport meets).