Eastern Bank separated itself from the pack two years ago by becoming the first state-chartered, community bank – aside from State Street – to cross $10 billion in assets. Earlier this year, Berkshire Bank one-upped Eastern by storming into Boston, making the city its headquarters and completing mergers that allowed the company to call itself the first regional bank based in Boston in decades.

But yesterday, both Eastern and Berkshire took a back seat as another player emerged to take hold of the Boston market.

The parent company of Rockland Trust announced yesterday that it would acquire the parent company of Hyde Park-based Blue Hills Bank in a deal that will give Rockland the largest deposit share in Massachusetts, the largest branch network and bring the company over $11 billion in assets.

The part cash, part stock transaction is valued at nearly $730 million, representing 178 percent of Blue Hills Bancorp’s current tangible book value.

The agreement provides that each Blue Hills Bancorp stockholder will receive 0.2308 per share of Rockland parent’s common stock, or roughly $25.80 per share, which is a 12 percent premium over the closing of Blue Hills stock on Wednesday. Blue Hills stockholders will also receive $5.25 in cash for each share of Blue Hills Bancorp common stock.

“This is a wonderful in-market transaction for us that offers excellent strategic fit and economics,” Christopher Oddleifson, president and CEO of Rockland Trust, said on a conference call this morning. “They (Blue Hills Bank) are in a very distinct neighborhood that we are not.”

The deal gives Oddleifson the presence in Boston and the surrounding area that he has always sought in places like Hyde Park, but also in surrounding suburbs like Dedham and Milton. Rockland came into Boston in 2015 when it acquired People’s Federal Savings Bank, giving it branches in Allston, Brighton and Jamaica Plain. In addition to its Hyde Park branches, Blue Hills Bank currently has branches in Back Bay, the Seaport and Dorchester.

Blue Hills Bank also owns naming rights to the 5,000-seat Blue Hills Bank Pavilion amphitheater, which could be in for a name change.

Some of Blue Hills’ branches are quite close to Rockland branches, including in Norwood and West Roxbury, and Oddleifson does expect some consolidation. But he expects the majority of Blue Hills branches will remain open and that Rockland will retain many Blue Hills employees.

Another benefit of the acquisition is that it bolsters Rockland’s presence in Cape Cod and on the surrounding islands by giving it a commanding presence in Nantucket – Blue Hills Bank owns Nantucket Bank and its three branches.

Rockland’s purchase of Blue Hills Bank continues Oddleifson’s acquisition-thirsty strategy and marks the 11th acquisition the bank has made since the turn of the century. Rockland acquired the roughly $360 million asset Milford National Bank at the end of May.

But the merger with Blue Hills Bank and its $2.7 billion in assets is by far the largest acquisition Rockland has made and is one of the largest bank deals in the Boston area in recent years.

The new branches and commercial relationships Blue Hills brings will be welcome for Rockland’s wealth management business. Rockland’s model, according to Oddleifson, gets 80 percent of its referrals in this sector from its branch network and commercial relationships.

For Blue Hills Bank, the deal ends what has been a successful run of growth and positive earnings for an institution that only eight years ago had less than $1 billion in assets and operated under the name Hyde Park Savings Bank.

Current CEO William Parent came aboard in 2010, changed the name, issued a partial initial public offering in 2014 and transitioned the bank’s focus to commercial lending. The bank is the second of four – along with Pilgrim Bank – to have issued an IPO in 2014 and then get acquired following the state’s three-year mandatory waiting period.

“This transaction creates a combined company with growth potential and considerable franchise value,” Parent said in a statement. “We are pleased to join Rockland Trust, a best in class partner that will benefit our customers, employees and the communities we serve while also providing an attractive return to our shareholders.”

Oddleifson said Parent, who he has known for some time now, approached him about the deal. Rockland Trust will incorporate three members of the board of directors at Blue Hills Bank to its board as part of the deal, which is expected to close in the first half of 2019.