In 1382 Richard von Büren who was then in the employ of the Count of Kyburg, was asked to be a co-signer on a loan for the Count. He was placing his personal fortune at risk if the Count were to default.
A excerpt of the agreement:
Obligation of 1382, Febr. 28
"Count Rudolf von Kyburg, County Count von Burgund, Count Berthold von Kyburg, his cousin, Konrad Sachs von Teibingen, Mayor of-Burgau, Johann Spiegler, church warden to Minstngen, Peter von Banmoss, Peter von Mattstetten, Burkard von Sumiswald, Squire, Erhard von Igliswil, Hans Burer, Aebi von Hasle, Erhard Grabenlier, citizen of Burgdorf, Peter von Lowenstein, citizen of Thun, Richard von Büren, Cuno Thurin, citizen of Bern, make known to all with this letter (document) that, together and undividedly because of a legally valid promissory note and because of a monetary debt, they owe the humble, man, Benjamin von Schlettsatt, citizen of Bern, 146 guilders of full weight and gold content. These [he] lent us in our need and out of friendship in cash. The above mentioned persons pledge to repay the debt to Master Benjamin, his heirs, or also to the person who is in the possession of this document on the coming Day of St. Michael (Sept. 29). In the event that the said debt need not be repaid with the consent of the owner of the document, there shall be paid during this time two pennies interest ("profit") per week per pound. In the event that the creditor demands restitution of the principal and of the interest, the debtors are obligated to pay immediately the principal and the owed interest. If the debtors do not comply with this obligation, the creditor is entitled to borrow fron Christians or Jews the entire requested amount, in full or only in part, against a weekly interest of two pennies per pound; this will cause no damages 1:0 the creditor, as the debtors will be responsible for all expenses resulting thereof in addition to the principal debt and the interest. All this the debtors pledge each one alone and all together."
This is interesting because the agreement was signed only months before the Counts of Kyburg launched the War of Berthoud against Bern, which they would ultimately lose.