Vasubandhu and Asanga were two influential Buddhist philosophers who played a crucial role in the development of Yogachara Buddhism. They were not only contemporaries but also brothers, making their relationship even more significant in the context of their contributions to this school of thought.

Yogachara, also known as the "Yogic Practice" or "Consciousness Only" school, emerged in India during the 4th century CE. It sought to provide a deeper understanding of the nature of reality and the human mind through the practice of meditation and introspection. The teachings of Yogachara were based on the Mahayana Buddhist texts, particularly the Lankavatara Sutra and the Yogacara Bhumi Sastra.

Vasubandhu and Asanga were born into a Brahmin family in the kingdom of Gandhara, in present-day Pakistan. They were both initially followers of the Sarvastivada school of Buddhism but later became disillusioned with its teachings and turned to the Mahayana tradition. They were also both students of the renowned Buddhist scholar and teacher, Maitreya.

Vasubandhu is considered the co-founder of Yogachara Buddhism, along with his brother Asanga. He is credited with writing several important texts, including the Abhidharmakosha, which is a comprehensive treatise on Buddhist philosophy. He also wrote the Vimsatika, a text that presents the Yogachara view of the nature of reality. Vasubandhu's contributions to Yogachara were crucial in establishing its philosophical foundations and shaping its doctrines.

Asanga, on the other hand, is known for his role in developing the practical aspects of Yogachara Buddhism. He is credited with writing the Mahayanasamgraha, which presents the Yogachara teachings in a concise and accessible manner. Asanga also wrote the Mahayana-sutra-alamkara-karika, which is a commentary on the Lankavatara Sutra. He also founded the Yogachara branch of Buddhism, known as the Yogachara-Svatantrika-Madhyamika, which combined Yogachara and Madhyamaka philosophies.

The relationship between Vasubandhu and Asanga was one of mutual respect and collaboration. They worked together to develop and propagate the teachings of Yogachara Buddhism, with Vasubandhu focusing on the theoretical aspects and Asanga on the practical aspects. Their shared background and training in Buddhist philosophy allowed them to build upon each other's ideas and refine the teachings of Yogachara.

In conclusion, the relationship between Vasubandhu and Asanga was crucial in the development of Yogachara Buddhism. They complemented each other's strengths and worked together to shape this school of thought into what it is today. Their contributions continue to influence Buddhist philosophy and practice, making them significant figures in the history of Buddhism.