"Letters Testamentary" is a Minnesota court order appointing a person as personal representative or executor of the Will of a deceased person.
The terminology "Letters" comes from Old English legal usage that meant a writ or order issued by a judge. "Testamentary" refers to the written document called a Will which provides for the distribution of the possessions of a loved one after he or she dies.
Letters Testamentary gives the person appointed the legal authority to stand in the shoes of the decedent. In other words, the personal representative can get any information about accounts or assets or manage the assets that the decedent had.