William Herschel discovered NGC 1084 = H I-64 = h264 on 10 Jan 1785 (sweep 355). He recorded "vB, pL, lE, mbM" and measured an accurate position.

The galaxy was observed 8 times at Birr Castle (earliest by Johnson Stoney on 12 Nov 1848). On 16 Oct 1855, assistant R.J. Mitchell called this a "Fine oval neb, has nucl, light mottled, sometimes I thought I saw a dark bay north of Nucl, certainly the neb is brighter along n and nf side than in the part intervening between that and the nucleus". Lassell's sketch shows a very tight spiral wrapping 1 1/2 revolutions around a stellar nucleus. He noted "A very obscure faint spiral nebula of apparently this form with power 760.?

200/250mm - 8" (10/13/81): bright, moderately large, elongated. Three mag 9-10 stars lie 13' N, 15' NNE and 16' NNW.

400/500mm - 17.5" (10/21/95): very bright, fairly large, elongated 2:1 SSW-NNE, 2.5'x1.2', broad concentration with a large bright core. Irregular mottled appearance or dust or dark lanes on the east side. The west side has a symmetric bulging appearance but there are dark indentations or bays on the NE and SE sides of the halo (probably between the spiral arms).

Notes by Steve Gottlieb