In addition to what others have said, from a historical perspective such bonds were the functional equivalent of stock. That is, these particular bonds effectiv

In addition to what others have said, from a historical perspective such bonds were the functional equivalent of stock. That is, these particular bonds effectively represented equity, not debt. Joint-stock, limited liability corporations are relatively recent, especially in terms of market liquidity and legal norms. Whereas the laws regarding bonds and bond payments are much older and were (and in many ways remain) much more consistent across all of Europe and, today, the world. A bond is a type of negotiable instrument, and laws regarding negotiable instruments--which also include checks, letters of credit, mortgages, etc--go back to at least the Medieval period in their literal terms, and in general terms to the Lex Mercatoria (i.e. merchant laws of the Mediterranean trading nations, including the Roman Empire, that were organically preserved through the Medieval period and even up to today). Other commercialized civilizations also had substantially similar laws. Bonds are a relatively safe investment for more than the reasons commonly recited today--e.g. hedging market volatility, etc.