In order to increase precision, dating the recombination was carried out using the recombinant region ALN2-1 and the recombination free ORF (ALN2-2). Overall, when compared to the outcome of ALN2-2, divergence times for ALN2-1 were younger and less precise, probably due to the low amount of informative data. For the sake of studying the recombination event, ideally three nodes should be scrutinized: Node ''r'' on Figure 3 estimates the actual recombination. It refers to the clustering of the LIV recombinant segment with the Neudoerfl strain which places tRE at a median of 76 (HPD: 45-160) years before origin. Accordingly, this time point is paramount and constitutes the lower bound of the estimate, but caution is advised when interpreting it as the definitive estimate. Indeed, it suffers from being inferred from a dataset comprising very short sequences. Moreover this analysis, carried out with a low level of prior enforcement, demonstrates a systematic bias towards younger antiquity. ''M'' and ''m'' are time points that refer respectively to the oldest estimate for the emergence of the major and minor parental lineages. Point ''M'' corresponds to the split of SSEV and LIV lineages, dated at a median of 1017 (HPD: 664 to 1510). Point ''m'' refers to the emergence of Neudoerfl, which corresponds to its split with the most closely related strain Hypr. However, few substitutions among the nine W-TBEV strains leads to poor phylogenetic resolution. Hence, a more conservative estimate for the onset of the minor parent would coincide with the divergence of the W-TBEV clade, placed at a median of 307 (HPD: 208 to 444) years. The next step aimed to retrieve divergence times for ''M'' and ''m'' with both increased accuracy (better locate the events in time) and increased precision (achieve narrower confidence intervals). We analyzed the largest available dataset for TBEV strains with collections dates (161 sequences); unfortunately, it only covers the Envelope glycoprotein (E) obtained from epidemiological studies. This brings on two problems: Firstly, this dataset is unable to target the actual recombination that occurred within the NS3 gene. Secondly, inference 1 has demonstrated that the E-gene presents the lowest rate of substitution among the viral genes, therefore it estimates older divergence dates than other portions of the genome. Although the former issue cannot be avoided, Esequences can nevertheless pinpoint which lineages would carry the recombinant element in a much larger tree. The latter issue can be tackled in a Bayesian framework by incorporating posterior information on divergence times derived from full-length coding sequences as prior distributions in an E-sequence analysis. The underlying rational is that by injecting information that pertains to all genes, bar E and the recombinant segment, we would be able to downplay the influence of the low substitution rate, while still combining all available evidence and avoiding circularity. We used BEAST inference 3 to calculate prior distributions for the root age and tMRCA(W-TBEV). The prior on the substitution rate was derived from the literature and not from BEAST inference 1 in order to avoid circularity in the use of data. Figure 5 depicts the outcome of BEAST inference 4, wherein the general tree summarizes the entire TBEV species evolutionary history and the enlarged chronogram gives median divergence dates within the W-TBEV, LIV, SSEV, GGEV, TSEV cluster.