There are several steps that parents can take to help their two year old sleep through the night undisturbed:

1. Establish a consistent bedtime routine. Start with a relaxing routine in the evening such as a warm bath, reading a story and singing a song. Ending the day with a similar routine will help your child wind down.

2. Introduce a calming activity. Create a calming atmosphere in the bedroom with soft music or soothing white noise. Help your child stay calm by engaging them in a quiet activity such as drawing or puzzles.

3. Make sure they have a comfortable bed and bedding. Ensure they have a comfortable mattress, a cozy blanket and pillows. Make sure their room is dark and cool.

4. Limit naps during the day. A regular nap schedule can help ensure your child is rested at night. However, try not to let naps run too late in the day as this can interfere with their nighttime sleep.

5. Set clear expectations about sleeping. Let your child know when it is time for bed and that they need to stay in bed until morning. If they do get up, calmly take them back to bed and remind them of the rules.

Following these tips can help your two year old sleep through the night undisturbed. With a consistent bedtime routine and clear expectations, your child should be well on their way to sleeping through the night.