Who created Brahma, Vishnu and Shiva ?

Who created Brahma, Vishnu and Shiva ? Lord Narayana (Purusha ) created Trimurti . I'll qoute from Ramayana and Mahabharata . Before the beginning of creation Brahma emerged from the navel of Vishnu . (Uk 91) “In earlier times, when all the worlds were drawn in, you used your own maya to lie down on the great ocean.In those ancient times, I(Brahma) was born from you. Purusha assumed the form of Vishnu to protect the universe and establish dharma According to the request of Brahma I was also born from a divine lotus, as resplendent as the sun, originating in your navel. You said that creation was my task and invested everything in me. O lord of the universe! Having taken up the burden invested on me, I worshipped you. Because you are more energetic than me, I asked you to protect creatures. Since that time, for the sake of protecting all creatures, you gave given up your eternal and invincible form and assumed the form of Vishnu Lord Shiva explains his origin in Mahabharata. "Maheswara said, 'Hari is superior to the Grandsire himself. He is the Eternal Purusha. Otherwise called Krishna, he is endued with the splendour of gold, and shines with effulgence like a second sun. Possessed of ten arms, he is endued with great energy, and is the slayer of the foes of the gods. Having a whorl on his breast, he has curly locks of hair on his head. He is worshipped by all the deities. Brahman has risen from his abdomen. I have sprung from his head, All the luminaries in the firmament have sprung from his hair. From the bristles on his body have sprung all the gods and Asuras. From his body have sprung the Rishis as also all the eternal worlds. He is the veritable abode of the Grandsire and the abode of all the gods besides. He is the Creator of this whole Earth, and He is the Lord of the three worlds He is also the Destroyer of all creatures mobile and immobile. He is verily the foremost of all the deities. He is their master. He is the chastiser of all foes. He is possessed of omniscience. He exists in everything. He is capable of going everywhere. He is of universal extent (pervading as he does everything). He is the Supreme Soul. He is the urger of all the senses. He covers the universe. He is the Supreme Lord. There is nothing in the three worlds that is superior to him. He is Eternal. He is the slayer of Madhu, and is otherwise called Govinda. Anusasana parva (148) There is also a reference in Adhyathma Ramayana written by Veda vyas . "The Supreme Spirit (Purusha) hath three condition, In the form of Brahma, he is the Creator, and in the form of Vishnu he is the Preserver, and in his form as Rudra, he is the Destroyer of the Universe". (Source : Mahabharata Vana Parva Section CCLXX)