Multilevel Inheritance occurs when a derived class is formed from another derived class.
Grandfather, father, and son are the perfect example to represent Multilevel Inheritance in C# −

Example
The following is an example stating the usage of multilevel inheritance in C#.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace Demo {
class Son : Father {
public void DisplayTwo() {
Console.WriteLine("Son.. ");
}
static void Main(string[] args) {
Son s = new Son();
s.Display();
s.DisplayOne();
s.DisplayTwo();
Console.Read();
}
}
class Grandfather {
public void Display() {
Console.WriteLine("Grandfather...");
}
}
class Father : Grandfather {
public void DisplayOne() {
Console.WriteLine("Father...");
}
}
}Output
Grandfather... Father... Son..