Fagales is one of the Orders in Fabidae, part of the Nitrogen‑fixing clade.
In the Plant theory the Nitrogen‑fixing clade is in Phases 5 to 7. In the Cronquist system only four families, Betulaceae, Corylaceae, Fagaceae and Ticodendraceae were placed in Fagales. In the Stebbins classification Fagales was part of the Hamamelidae, which contained many wind pollinated trees. Many Families from that clade have been transferred to compeltely different positions in the Apg3 classification like Platanaceae, Ulmaceae, and Hamamelidaceae.
In the Plant theory Fagales is placed in Phase 4. This corresponds with Fagales being mostly of big trees. The placement in Subphases is tentative.