Based on measurements performed between 2015 and 2018 we provide a characterization of the Bitcoin P2P network. The characterization enables the parametrization and validation of simulation models and the assessment of the reliability of real-world experiments. Furthermore, the network characterization provides insights into the behavior of peers and their operators. For instance, we provide evidence that Sybil events happened in the past in the Bitcoin P2P network. Additionally, our measurements show that the performance and anonymity of transaction and block propagation has been improved by implementation and protocol changes.