The earliest Slingsby family tree I have found so far is at http://www.familysearch.org/eng/default.asp Search for "Slingsby" and page down through the results. The first Slingsby with a clear date of birth is John de Slingsby (born 1289). He was the son of John de Slingsby (no dates) and Agnes de Stodleigh (hence the Stodleigh Crestin Knaresborough Parish Church)
The Brayton Tree shows the Slingsbys of Brayton, near Selby North Yorkshire as developed by Kate Slingsby and Anita Creese. A specific branch of the tree is highlighted and contains more detailed information which can be "zoomed in" on by clicking on the appropriate colour coded link. In these more detailed "tree branches" you can click on individual names (highlighted blue) for further information about that person.
The Idle Tree shows the Slingsbys of Idle, West
Yorkshire kindly provided by Barbara and Linda and progresses to a branch of the
family that emigrated to the US in 1910. There is more detail to add to this
tree, hopefully in the next few weeks.
The Pudsey St Lawrence tree has been provided by Leonie Slingsby
If you can add information to these trees or correct them, or have a link into them, you can contact me, at any time