Vibrio cholerae has caused seven cholera pandemics since 1817, but bacterial strains are currently only available for the 6th and 7th pandemics. The El Tor biotype 7th pandemic began in 1961 in Indonesia, but did not originate directly from the classical biotype 6th pandemic strain. We used PacBio sequencing to get effectively perfect sequences of strains isolated from 1930 to 1964, covering the evolution from the first available El Tor biotype strain to the start of the 7th pandemic. We defined six stages leading to the pandemic strain and reveal all key events mutation, recombination and gain/loss events. The 7th pandemic originated from a non-pathogenic strain in the Middle East, first observed in 1897. It subsequently underwent explosive diversification, including the spawning of the pandemic lineage. This rapid diversification suggests that, when first observed, the strain had only recently arrived in the Middle East, possibly from the Asian homeland of cholera. The lineage migrated to Makassar, Indonesia, where it gained the important virulence-associated elements VSP-I, VSP-II and CTXET by 1954, and then became pandemic in 1961 after only 12 additional mutations. While in the Middle East and Makassar the strain gained genes that had been in the sixth pandemic and these were important in generating the 7th pandemic strain, suggesting the presence of V. cholera in specific niches in the Middle East and Makassar, as the sources of these genes (Hu et al. 2016. PNAS. 10.1073/pnas.1608732113). The tree data is in a form that allows updating of the tree with new data and we will illustrate this with data on strains isolated in China.