In this post, we’ll see how to create a site-collection using SharePoint 2013 CSOM in SharePoint Online. We’ll be using a console application for the purpose of demonstration.

Open Visual Studio 2013 –> File –> New –> Console Application and name it as ‘CreateSiteCollCSOM’.

Add references to the following assemblies

Microsoft.SharePoint.Client.dll

Microsoft.SharePoint.Client.runtime.dll

Microsoft.Online.SharePoint.Client.Tenant.dll

.

The Microsoft.Online.SharePoint.Client.Tenant.dll will be available in the location C:Program FilesSharePoint Client ComponentsAssemblies, if the SharePoint Client Components SDK is installed.

Import the following namespaces at the top of Program.cs

using  Microsoft.SharePoint.Client;
using System.Security;
using Microsoft.Online.SharePoint.TenantAdministration;

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static void Main(string[] args)
        {
            


            using (ClientContext oClientContext = new ClientContext("https://yoursite-admin.sharepoint.com"))
            {
                //Assign User Id for your SharePoint Online tenant     
                string UserName = "userid@yoursite.onmicrosoft.com";

                //Assign password for your SharePoint online tenant
                string Password = "password";

                //Create a SecureString object from password string, needed for SharePointOnlineCredentials class
                SecureString SecurePassword = GetSecureString(Password);

                oClientContext.Credentials = new SharePointOnlineCredentials(UserName, SecurePassword);
                

                var oTenant = new Tenant(oClientContext);

                var oSiteCreationProperties = new SiteCreationProperties();


                //Set the url of site-collection to be created
                oSiteCreationProperties.Url = "https://yoursite.sharepoint.com/sites/TestSiteColl";

                //Set the title of site
                oSiteCreationProperties.Title = "Test SiteColl from code";

                //set the site-collection owner
                oSiteCreationProperties.Owner = "userid@yoursite.onmicrosoft.com";

                //set the template of site-collection to be created as TeamSite
                oSiteCreationProperties.Template = "STS#0";

                //set the storge maxium level in MB
                oSiteCreationProperties.StorageMaximumLevel = 200;

                oSiteCreationProperties.UserCodeMaximumLevel = 100;



                SpoOperation oSpoOperation = oTenant.CreateSite(oSiteCreationProperties);

                oClientContext.Load(oTenant);

                oClientContext.Load(oSpoOperation, i=>i.IsComplete);
                oClientContext.ExecuteQuery();

               

                Console.WriteLine("SiteCollection successfully reated");




            }




        }

        private static SecureString GetSecureString(String Password)
        {
            SecureString oSecurePassword = new SecureString();

            foreach (Char c in Password.ToCharArray())
            {
                oSecurePassword.AppendChar(c);

            }
            return oSecurePassword;
        }

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{
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color: black;
font-family: consolas, “Courier New”, courier, monospace;
background-color: #ffffff;
/*white-space: pre;*/
}
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.csharpcode .rem { color: #008000; }
.csharpcode .kwrd { color: #0000ff; }
.csharpcode .str { color: #006080; }
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.csharpcode .asp { background-color: #ffff00; }
.csharpcode .html { color: #800000; }
.csharpcode .attr { color: #ff0000; }
.csharpcode .alt
{
background-color: #f4f4f4;
width: 100%;
margin: 0em;
}
.csharpcode .lnum { color: #606060; }