A Stammbuch, or album amicorum, is a kind of friendship book that was kept mainlyby students at German-speaking universities. It was primarily used to collect personalmessages – Einträge, or entries – from fellow students and professors. The traditionof keeping these albums emerged in Germany during the Reformation and subsequentlyspread, including to Scandinavia. It persisted right into the 20th century. Analbum amicorum usually consists of a volume with originally blank pages on which the entries have been written. A typical entry consists of a quotation or maxim at thetop of the page, followed by a dedication, a notation of the place and date of the entry,and a signature. The commonest languages used are German and Latin, but entries in Classical Greek, Hebrew, French and many other European vernaculars also occur.Albums are often artistically decorated with drawings and coats of arms.Onomasticians have made far too little use of albums of this kind. The present articleemphasises that they can be an important source of new knowledge for research,above all, into historical personal names. With reference to an earlier study, it is shownfor example how material from alba amicorum changes our picture of how the Chancellorof Sweden, Axel Oxenstierna (1583–1654), wrote his name. Contrary to theclaims of earlier scholars, it emerges that Oxenstierna did in fact use a patronymic.The article also describes how material from these albums has revealed a new earliestrecord of a woman using a married name in Sweden, from 1654, when AgnesMargredhtWagthmejster geboren won Helmstedt employed such a name in an albumentry. Material from alba amicorum can in addition provide new insights into the useof patronymics and hereditary surnames in historical times.