Distribution of YSOs in W5-E. Top: Class II YSOs and exciting stars. The red circles are the YSOs identified as Class II sources by KOE08. The green crosses are the massive exciting stars of the H ii regions (from east to west) Sh 201, AFGL 4029, W5-E, A & B between W5-E and W5-W, and W5-W. The green line shows the east-west filament inside which we suggest that the exciting stars of W5-E and W5-W formed first. The underlying grey-scale image is the Herschel-SPIRE 350 μm map. Bottom: the youngest sources, Class I and candidate Class 0 YSOs. The red dots are the YSOs identified as Class I sources by KOE08. The orange circles are the 100 μm point sources, mostly Stage I YSOs. The large full orange circles are our candidate Class 0 sources. The blue circles are for the CO outflows detected by Ginsburg et al. (2011). The underlying grey-scale image is the column density map.