Jakob Ammann was born on 12 February 1644 in Erlenbach im Simmental, Canton of Bern, Switzerland, to Michael and Anna (née Rupp) Ammann. Erlenbach church records note the baptism of a Jacob Ammann on 12 February 1644, who was probably the Jakob Ammann from whom the Amish received their name. His grandfather has been identified as Ulrich Ammann. All three Ammanns were tailors. Jakob was third in a family of six children. He probably received limited formal education. On 37 official documents signed by Jakob, only his initials appear, with most of them having a nearby note that Jakob was not able to write, so he only "made his mark". However, on three documents, his signed name does appear, although twice it was probably written for him by someone else; once, with the same style of writing as his initials, appear the poorly formed letters "J. AMME", which is assumed to be his own writing. Because he asked for letters to be read in one meeting, it is assumed he was not able to read, or possibly only poorly. He did better financially than the average person of his time.