The market capitalisation of international bond markets is much larger than that of international equity markets. However, compared to the large body of literature on international equity market linkages, there are far fewer empirical studies of bond systemic risk or international bond market co-movements. The extent of international bond market linkages merits investigation, as it may have important implications for the cost of financing fiscal deficit, monetary policymaking independence, modelling and forecasting long-term interest rates, and bond portfolio diversification. In this paper, we investigate the relative influence of systemic and idiosyncratic risk factors on yield spreads over 10-year German government securities during the seven years after the beginning of Monetary Integration. We estimate both panel regressions for the two groups of EU-15 countries (EMU and non-EMU) and specific-country regressions for the nine countries in the EMU group and the three countries in the non-EMU group. All estimations include both domestic (differences in market liquidity and credit risk) and international risk factors. The results present clear evidence that it was mostly idiosyncratic rather than systemic risk factors that drove the evolution of 10-year yield spread differentials over Germany in all EMU countries during the seven years after the beginning of Monetary Integration. Conversely, in the case of non-EMU countries, adjusted yield spreads (corrected from the foreign exchange factor) are influenced more by systemic risk factors. The fact that these countries do not share a common Monetary Policy might explain these results, which may show that government bonds from EMU countries have a better safe-haven status that those of non-EMU countries.