Final answer:
The four hymns by Guru Nanak that allude to the invasions by Babar are collectively known as Babar Vani in Sikh literature.
Step-by-step explanation:
In Sikh literature, the four hymns by Guru Nanak that allude to the invasions by Babar (1483- 1530 A.D.) are collectively known as Babar Vani. These hymns provide a historical account and reflect the social and political conditions of the time during Babar's invasion. Guru Nanak Dev Ji, as the founder of Sikhism, chronicled these events through his poetic compositions, which are revered as part of Sikh sacred literature.