The Shamrock Trinity Series by Kay Hooper, Iris Johansen, Fayrene Preston

Heirs to a great dynasty, the Delaney brothers were united by blood, united by devotion to their rugged land ... and known far and wide as THE SHAMROCK TRINITY. Powerful men... rakes and charmers... they needed only love to make their lives complete. Rafe Delaney was a heartbreaker whose ebony eyes held laughing devils and whose lilting voice could charm any lady -- or any horse -- until a stallion named Diablo left him in the dust... moreHeirs to a great dynasty, the Delaney brothers were united by blood, united by devotion to their rugged land ... and known far and wide as THE SHAMROCK TRINITY. Powerful men... rakes and charmers... they needed only love to make their lives complete. Rafe Delaney was a heartbreaker whose ebony eyes held laughing devils and whose lilting voice could charm any lady -- or any horse -- until a stallion named Diablo left him in the dust. It took Maggie O'Riley to work her magic on the impossible horse...and on his bold owner. No woman had jolted Rafe Delaney's heart until this tiny dynamo had come to Shamrock Ranch; now her grace and strength made him yearn to share the raw beauty of his land, to teach her the exquisite pleasure of yielding to the heat inside her. Maggie was stirred by Rafe's passion, but would his reputation and her ambition keep their kindred spirits apart? less

Some men were made to fight dragons, Sierra Smith thought when she met York Delaney. The rebel brother had roamed the world for years before calling the wild, rough mining town of Hell's Bluff home. York gazed at her with barely leashed violence before taking her in his arms, but the spirited young woman who'd penetrated his renegade's paradise had awakened a savage and tender possessiveness he'd never suspected in himself... moreSome men were made to fight dragons, Sierra Smith thought when she met York Delaney. The rebel brother had roamed the world for years before calling the wild, rough mining town of Hell's Bluff home. York gazed at her with barely leashed violence before taking her in his arms, but the spirited young woman who'd penetrated his renegade's paradise had awakened a savage and tender possessiveness he'd never suspected in himself. Sierra had known loneliness and isolation too--enough to realize that York's restlessness had everything to do with finding out where he belonged. Could she convince him that love was a place, that the refuge he'd always sought was in her arms? less

Cara Winston appeared as a fantasy, racing on horseback to catch the day's last light -- her silver hair glistening, her dress the color of the Arizona sunset...and Burke Delaney wanted her. She was on his horse, on his land: she would have to belong to him too. But Cara was quicksilver, impossible to hold, a wild creature whose scent was midnight flowers and sweet grass... moreCara Winston appeared as a fantasy, racing on horseback to catch the day's last light -- her silver hair glistening, her dress the color of the Arizona sunset...and Burke Delaney wanted her. She was on his horse, on his land: she would have to belong to him too. But Cara was quicksilver, impossible to hold, a wild creature whose scent was midnight flowers and sweet grass. Burke had always taken what he wanted, by willing it or fighting for it; Cara cherished her freedom and refused to believe his love would last. Could he make her see he'd captured her to have and hold forever? less