 In 1540 he led an expedition of 150 Spaniards into Chile, where he defeated a large force of indigenous natives and founded Santiago in 1541.He extended Spanish rule south to the Biobío River in 1546, fought again in Peru (1546 – 48), and returned to Chile as governor in 1549.He began to conquer Chile south of the Biobío and founded Concepción in 1550.