diff --git a/app/models/spree/classification.rb b/app/models/spree/classification.rb
new file mode 100644
index 0000000000..0b668a068b
--- /dev/null
+++ b/app/models/spree/classification.rb
@@ -0,0 +1,21 @@
+# frozen_string_literal: true
+
+module Spree
+  class Classification < ActiveRecord::Base
+    self.table_name = 'spree_products_taxons'
+    belongs_to :product, class_name: "Spree::Product", touch: true
+    belongs_to :taxon, class_name: "Spree::Taxon", touch: true
+
+    before_destroy :dont_destroy_if_primary_taxon
+
+    private
+
+    def dont_destroy_if_primary_taxon
+      return unless product.primary_taxon == taxon
+
+      errors.add :base, I18n.t(:spree_classification_primary_taxon_error, taxon: taxon.name,
+                                                                          product: product.name)
+      false
+    end
+  end
+end
diff --git a/app/models/spree/classification_decorator.rb b/app/models/spree/classification_decorator.rb
deleted file mode 100644
index 20608bad94..0000000000
--- a/app/models/spree/classification_decorator.rb
+++ /dev/null
@@ -1,15 +0,0 @@
-Spree::Classification.class_eval do
-  belongs_to :product, class_name: "Spree::Product", touch: true
-  belongs_to :taxon, class_name: "Spree::Taxon", touch: true
-
-  before_destroy :dont_destroy_if_primary_taxon
-
-  private
-
-  def dont_destroy_if_primary_taxon
-    if product.primary_taxon == taxon
-      errors.add :base, I18n.t(:spree_classification_primary_taxon_error, taxon: taxon.name, product: product.name)
-      false
-    end
-  end
-end
diff --git a/app/models/spree/taxon.rb b/app/models/spree/taxon.rb
new file mode 100644
index 0000000000..4e29c068ce
--- /dev/null
+++ b/app/models/spree/taxon.rb
@@ -0,0 +1,113 @@
+# frozen_string_literal: true
+
+module Spree
+  class Taxon < ActiveRecord::Base
+    acts_as_nested_set dependent: :destroy
+
+    belongs_to :taxonomy, class_name: 'Spree::Taxonomy', touch: true
+    has_many :classifications, dependent: :destroy
+    has_many :products, through: :classifications
+
+    before_create :set_permalink
+
+    validates :name, presence: true
+
+    has_attached_file :icon,
+                      styles: { mini: '32x32>', normal: '128x128>' },
+                      default_style: :mini,
+                      url: '/spree/taxons/:id/:style/:basename.:extension',
+                      path: ':rails_root/public/spree/taxons/:id/:style/:basename.:extension',
+                      default_url: '/assets/default_taxon.png'
+
+    include Spree::Core::S3Support
+    supports_s3 :icon
+
+    # Indicate which filters should be used for this taxon
+    def applicable_filters
+      []
+    end
+
+    # Return meta_title if set otherwise generates from root name and/or taxon name
+    def seo_title
+      if meta_title
+        meta_title
+      else
+        root? ? name : "#{root.name} - #{name}"
+      end
+    end
+
+    # Creates permalink based on Stringex's .to_url method
+    def set_permalink
+      if parent.present?
+        self.permalink = [parent.permalink, permalink_end].join('/')
+      elsif permalink.blank?
+        self.permalink = name.to_url
+      end
+    end
+
+    # For #2759
+    def to_param
+      permalink
+    end
+
+    def active_products
+      scope = products.active
+      scope
+    end
+
+    def pretty_name
+      ancestor_chain = ancestors.inject("") do |name, ancestor|
+        name += "#{ancestor.name} -> "
+      end
+      ancestor_chain + name.to_s
+    end
+
+    # Find all the taxons of supplied products for each enterprise, indexed by enterprise.
+    # Format: {enterprise_id => [taxon_id, ...]}
+    def self.supplied_taxons
+      taxons = {}
+
+      Spree::Taxon.
+        joins(products: :supplier).
+        select('spree_taxons.*, enterprises.id AS enterprise_id').
+        each do |t|
+          taxons[t.enterprise_id.to_i] ||= Set.new
+          taxons[t.enterprise_id.to_i] << t.id
+        end
+
+      taxons
+    end
+
+    # Find all the taxons of distributed products for each enterprise, indexed by enterprise.
+    # May return :all taxons (distributed in open and closed order cycles),
+    # or :current taxons (distributed in an open order cycle).
+    #
+    # Format: {enterprise_id => [taxon_id, ...]}
+    def self.distributed_taxons(which_taxons = :all)
+      ents_and_vars = ExchangeVariant.joins(exchange: :order_cycle).merge(Exchange.outgoing)
+        .select("DISTINCT variant_id, receiver_id AS enterprise_id")
+
+      ents_and_vars = ents_and_vars.merge(OrderCycle.active) if which_taxons == :current
+
+      taxons = Spree::Taxon
+        .select("DISTINCT spree_taxons.id, ents_and_vars.enterprise_id")
+        .joins(products: :variants_including_master)
+        .joins("
+          INNER JOIN (#{ents_and_vars.to_sql}) AS ents_and_vars
+          ON spree_variants.id = ents_and_vars.variant_id")
+
+      taxons.each_with_object({}) do |t, ts|
+        ts[t.enterprise_id.to_i] ||= Set.new
+        ts[t.enterprise_id.to_i] << t.id
+      end
+    end
+
+    private
+
+    def permalink_end
+      return name.to_url if permalink.blank?
+
+      permalink.split('/').last
+    end
+  end
+end
diff --git a/app/models/spree/taxon_decorator.rb b/app/models/spree/taxon_decorator.rb
deleted file mode 100644
index f2c6f1e20a..0000000000
--- a/app/models/spree/taxon_decorator.rb
+++ /dev/null
@@ -1,47 +0,0 @@
-Spree::Taxon.class_eval do
-  has_many :classifications, dependent: :destroy
-
-  # Indicate which filters should be used for this taxon
-  def applicable_filters
-    fs = []
-    # fs << Spree::ProductFilters.distributor_filter if Spree::ProductFilters.respond_to? :distributor_filter
-    fs
-  end
-
-  # Find all the taxons of supplied products for each enterprise, indexed by enterprise.
-  # Format: {enterprise_id => [taxon_id, ...]}
-  def self.supplied_taxons
-    taxons = {}
-
-    Spree::Taxon.
-      joins(products: :supplier).
-      select('spree_taxons.*, enterprises.id AS enterprise_id').
-      each do |t|
-        taxons[t.enterprise_id.to_i] ||= Set.new
-        taxons[t.enterprise_id.to_i] << t.id
-      end
-
-    taxons
-  end
-
-  # Find all the taxons of distributed products for each enterprise, indexed by enterprise.
-  # May return :all taxons (distributed in open and closed order cycles),
-  # or :current taxons (distributed in an open order cycle).
-  #
-  # Format: {enterprise_id => [taxon_id, ...]}
-  def self.distributed_taxons(which_taxons = :all)
-    ents_and_vars = ExchangeVariant.joins(exchange: :order_cycle).merge(Exchange.outgoing)
-      .select("DISTINCT variant_id, receiver_id AS enterprise_id")
-
-    ents_and_vars = ents_and_vars.merge(OrderCycle.active) if which_taxons == :current
-
-    taxons = Spree::Taxon
-      .select("DISTINCT spree_taxons.id, ents_and_vars.enterprise_id").joins(products: :variants_including_master)
-      .joins("INNER JOIN (#{ents_and_vars.to_sql}) AS ents_and_vars ON spree_variants.id = ents_and_vars.variant_id")
-
-    taxons.each_with_object({}) do |t, ts|
-      ts[t.enterprise_id.to_i] ||= Set.new
-      ts[t.enterprise_id.to_i] << t.id
-    end
-  end
-end
diff --git a/app/models/spree/taxonomy.rb b/app/models/spree/taxonomy.rb
new file mode 100644
index 0000000000..2934281b4d
--- /dev/null
+++ b/app/models/spree/taxonomy.rb
@@ -0,0 +1,24 @@
+# frozen_string_literal: true
+
+module Spree
+  class Taxonomy < ActiveRecord::Base
+    validates :name, presence: true
+
+    has_many :taxons
+    has_one :root, -> { where parent_id: nil }, class_name: "Spree::Taxon", dependent: :destroy
+
+    after_save :set_name
+
+    default_scope -> { order("#{table_name}.position") }
+
+    private
+
+    def set_name
+      if root
+        root.update_column(:name, name)
+      else
+        self.root = Taxon.create!(taxonomy_id: id, name: name)
+      end
+    end
+  end
+end
diff --git a/spec/models/spree/taxon_spec.rb b/spec/models/spree/taxon_spec.rb
index 54a0069da9..e6d55b4b23 100644
--- a/spec/models/spree/taxon_spec.rb
+++ b/spec/models/spree/taxon_spec.rb
@@ -1,7 +1,11 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 module Spree
   describe Taxon do
+    let(:taxon) { Spree::Taxon.new(name: "Ruby on Rails") }
+
     let(:e) { create(:supplier_enterprise) }
     let!(:t1) { create(:taxon) }
     let!(:t2) { create(:taxon) }
@@ -46,5 +50,51 @@ module Spree
         end.to change { taxon2.reload.updated_at }
       end
     end
+
+    context "set_permalink" do
+      it "should set permalink correctly when no parent present" do
+        taxon.set_permalink
+        expect(taxon.permalink).to eq "ruby-on-rails"
+      end
+
+      it "should support Chinese characters" do
+        taxon.name = "你好"
+        taxon.set_permalink
+        expect(taxon.permalink).to eq 'ni-hao'
+      end
+
+      context "with parent taxon" do
+        before do
+          allow(taxon).to receive_messages parent_id: 123
+          allow(taxon).to receive_messages parent: build(:taxon, permalink: "brands")
+        end
+
+        it "should set permalink correctly when taxon has parent" do
+          taxon.set_permalink
+          expect(taxon.permalink).to eq "brands/ruby-on-rails"
+        end
+
+        it "should set permalink correctly with existing permalink present" do
+          taxon.permalink = "b/rubyonrails"
+          taxon.set_permalink
+          expect(taxon.permalink).to eq "brands/rubyonrails"
+        end
+
+        it "should support Chinese characters" do
+          taxon.name = "我"
+          taxon.set_permalink
+          expect(taxon.permalink).to eq "brands/wo"
+        end
+      end
+    end
+
+    # Regression test for Spree #2620
+    context "creating a child node using first_or_create" do
+      let(:taxonomy) { create(:taxonomy) }
+
+      it "does not error out" do
+        expect { taxonomy.root.children.where(name: "Some name").first_or_create }.not_to raise_error
+      end
+    end
   end
 end
diff --git a/spec/models/spree/taxonomy_spec.rb b/spec/models/spree/taxonomy_spec.rb
new file mode 100644
index 0000000000..2ead3dcc0e
--- /dev/null
+++ b/spec/models/spree/taxonomy_spec.rb
@@ -0,0 +1,19 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Spree::Taxonomy do
+  context "#destroy" do
+    before do
+      @taxonomy = create(:taxonomy)
+      @root_taxon = @taxonomy.root
+      @child_taxon = create(:taxon, taxonomy_id: @taxonomy.id, parent: @root_taxon)
+    end
+
+    it "should destroy all associated taxons" do
+      @taxonomy.destroy
+      expect{ Spree::Taxon.find(@root_taxon.id) }.to raise_error(ActiveRecord::RecordNotFound)
+      expect{ Spree::Taxon.find(@child_taxon.id) }.to raise_error(ActiveRecord::RecordNotFound)
+    end
+  end
+end