XDocument Root

using System;//from j  a  va 2  s.com
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Xml.Linq;

class Program
{
    static void Main()
    {
        var styleInstruction = new XProcessingInstruction("xml-stylesheet", "href='styles.css' type='text/css'");

        var docType = new XDocumentType("html", "", "", null);

        XNamespace ns = "http://www.w3.org/1999/xhtml";
        var root = new XElement(ns + "html", new XElement(ns + "head",
                new XElement(ns + "title", "An XHTML page")), new XElement(ns + "body",
                new XElement(ns + "p", "This is the content"))
            );

        var doc = new XDocument(
               new XDeclaration("1.0", "utf-8", "no"), new XComment("Reference a stylesheet"), styleInstruction,
              docType, root);

        doc.Save("test.html");

        Console.WriteLine(doc.Root.Name.LocalName); // html 
        XElement bodyNode = doc.Root.Element(ns + "body");
        Console.WriteLine(bodyNode.Document == doc);  // True
    }
}